Mr. Wang has 30000 yuan in his hand and wants to buy the three-year treasury bonds with an annual interest rate of 2.89%. When he arrives at the bank, the remaining treasury bonds are less than 30000 yuan. After Mr. Wang buys all these treasury bonds, the remaining money is deposited in a three-year fixed-term bank deposit with an annual interest rate of 2.7%, and he has to pay 20% interest tax when due How many yuan of treasury bills did you buy at the end of the year and how much yuan did you deposit in the bank?

Mr. Wang has 30000 yuan in his hand and wants to buy the three-year treasury bonds with an annual interest rate of 2.89%. When he arrives at the bank, the remaining treasury bonds are less than 30000 yuan. After Mr. Wang buys all these treasury bonds, the remaining money is deposited in a three-year fixed-term bank deposit with an annual interest rate of 2.7%, and he has to pay 20% interest tax when due How many yuan of treasury bills did you buy at the end of the year and how much yuan did you deposit in the bank?

Let's say X Yuan for treasury bills and Y yuan for bank deposit. According to the meaning, we can get x + y = 30000 30000 + 3 × 2.89% x + 3 × 2.7% Y (1 − 20%) = 32338.2, and the solution is x = 18000y = 12000. A: Mr. Wang bought 18000 yuan treasury bills and deposited 12000 yuan in the bank

5 (a-b) & 178; - 3 (a-b) & 178; - 7 (a-b) & 178; + 7 (a-b) process answer!
5(a-b)²-3(a-b)²-7(a-b)²+7(a-b)

Because a ＞ B ＞ 0, B (A &; b) ≤（
b+a−b
two
)2 ＝
a2
four
,
So A2+
one
b(a−b)
≥a2+
four
a2
≥4,
if and only if
b＝a−b
a2＝2
, i.e
a＝
two
b＝
two
two
Take the equal sign when the time is over
So A2+
one
b(a−b)
The minimum value of is 4,
So the answer is: 4

To solve the problem of crystallization of scientific substances in water, we should write out the formula and process,
At 20 ℃, the saturated solution of a substance is 2702g, and the solid of the substance is 7.2g after evaporation. What is the solubility of the substance at 20 ℃?

7.2/2702*100=0.266469

All the formulas of algebra in junior high school,

Mathematics formula in junior high school
one
There is only one straight line through two points
two
The shortest line segment between two points
three
The complements of the same or equal angles are equal
four
The remainder of the same or equal angle is equal
five
There is and only one line perpendicular to a known line passing through a point
six
Among all the line segments connected by a point outside the line and the points on the line, the vertical line segment is the shortest
seven
Axiom of parallelism
Passing through a point outside the line, there is and only one line parallel to the line
eight
If both lines are parallel to the third line, the two lines are parallel to each other
nine
The two lines are parallel
ten
The internal stagger angles are equal and the two lines are parallel
eleven
The inner angles of the same side complement each other, and the two lines are parallel
twelve
Two straight lines are parallel and the same angle is equal
thirteen
Two straight lines are parallel, and the internal stagger angle is equal
fourteen
The two lines are parallel and the inner angles of the same side are complementary
fifteen
theorem
The sum of two sides of a triangle is greater than the third
sixteen
inference
The difference between the two sides of the triangle is less than the third side
seventeen
Sum theorem of internal angles of triangles
The sum of the three internal angles of a triangle is equal to
180°
eighteen
inference
one
Two acute angles of right triangle complement each other
nineteen
inference
two
An outer angle of a triangle is equal to the sum of two inner angles not adjacent to it
twenty
inference
three
An outer angle of a triangle is greater than any inner angle not adjacent to it
twenty-one
The corresponding sides and angles of congruent triangles are equal
twenty-two
Edge corner edge axiom
(SAS)
There are two congruent triangles with equal angles between two sides
twenty-three
Corner edge corner axiom
( ASA)
Two congruent triangles with two equal angles and their clamped edges
twenty-four
inference
(AAS)
Two congruent triangles with two corners and the opposite side of one of the corners corresponding to equal
twenty-five
Edge edge axiom
(SSS)
Two congruent triangles with three equal sides
twenty-six
The axiom of hypotenuse and right angle
(HL)
Congruence of two right triangles with an equal hypotenuse and a right edge
twenty-seven
theorem
one
The distance from the point on the bisector of the angle to both sides of the angle is equal
twenty-eight
theorem
two
A point at the same distance to both sides of a corner, on the bisector of that corner
twenty-nine
The bisector of an angle is the set of all points with equal distances to both sides of the angle
thirty
Property theorem of isosceles triangle
The two base angles of an isosceles triangle are equal
(
I.e. equal sides and equal angles)
thirty-one
inference
one
The bisector of the vertex of an isosceles triangle bisects the bottom and is perpendicular to the bottom
thirty-two
The bisector of the vertex, the middle line on the bottom and the height on the bottom of an isosceles triangle coincide with each other
thirty-three
inference
three
Every angle of an equilateral triangle is equal, and every angle is equal to
60°
thirty-four
Judgement theorem of isosceles triangle
If two angles of a triangle are equal, then the opposite sides of the two angles are equal (equal angle to equal side)
thirty-five
inference
one
A triangle with three equal angles is an equilateral triangle
thirty-six
inference
two
There is an angle equal to
60°
An isosceles triangle is an equilateral triangle
thirty-seven
In a right triangle, if an acute angle equals
30°
So the right angle it faces is half of the hypotenuse
thirty-eight
The center line on the hypotenuse of a right triangle is equal to half of the hypotenuse
thirty-nine
theorem
The distance between the point on the vertical bisector of a line segment and the two ends of the line segment is equal
forty
Inverse theorem
A point equal to the distance between two ends of a line segment is on the vertical bisector of the line segment
forty-one
The vertical bisector of a line segment can be regarded as a set of all points with the same distance from the two ends of the line segment
forty-two
theorem
one
Two figures symmetrical about a line are holomorphic
forty-three
theorem
two
If two figures are symmetrical about a line, the axis of symmetry is the vertical bisector of the line connecting the corresponding points
forty-four
theorem
three
Two figures are symmetrical about a line. If their corresponding line segments or extension lines intersect, then the intersection point is on the axis of symmetry
forty-five
Inverse theorem
If the line connecting the corresponding points of two figures is vertically bisected by the same line, then the two figures are symmetrical about the line
forty-six
Pythagorean theorem
Two right sides of a right triangle
a
、
b
The sum of squares of is equal to the hypotenuse
c
The square of
a^2+b^2=c^2
forty-seven
Inverse theorem of Pythagorean theorem
If the three sides of a triangle are long
a
、
b
、
c
It matters
a^2+b^2=c^2
So this triangle is a right triangle
forty-eight
theorem
The sum of internal angles of a quadrilateral is equal to
360°
forty-nine
The sum of the external angles of a quadrilateral is equal to
360°
fifty
Sum theorem of interior angles of polygon
n
The sum of the interior angles of a polygon is equal to（
n-2
）
×
180°
fifty-one
inference
The sum of exterior angles of any polygon is equal to
360°
fifty-two
Property theorem of parallelogram
one
The diagonal equality of parallelogram
fifty-three
Property theorem of parallelogram
two
The opposite sides of a parallelogram are equal
fifty-four
inference
The parallel line segments sandwiched between two parallel lines are equal
fifty-five
Property theorem of parallelogram
three
The diagonals of parallelograms are bisected
fifty-six
Judgement theorem of parallelogram
one
Two groups of diagonally equal quadrilaterals are parallelograms
fifty-seven
Judgement theorem of parallelogram
two
Two groups of quadrilateral whose opposite sides are equal are parallelogram
fifty-eight
Judgement theorem of parallelogram
three
A quadrilateral whose diagonals are bisected is a parallelogram
fifty-nine
Judgement theorem of parallelogram
four
A group of parallelograms whose opposite sides are parallel and equal are parallelograms
sixty
Rectangle property theorem
one
The four corners of a rectangle are right angles
sixty-one
Rectangle property theorem
two
The diagonals of rectangles are equal
sixty-two
Rectangle theorem
one
A quadrilateral with three right angles is a rectangle
sixty-three
Rectangle theorem
two
A parallelogram with equal diagonals is a rectangle
sixty-four
Diamond property theorem
one
All four sides of the diamond are equal
sixty-five
Diamond property theorem
two
The diagonals of the diamond are perpendicular to each other, and each diagonal is divided into a group of diagonals
sixty-six
Rhombic area
=
Half of the diagonal product, i.e
S=
（
a×
b
）
÷
two
sixty-seven
Diamond decision theorem
one
A quadrilateral whose four sides are equal is a diamond
sixty-eight
Diamond decision theorem
two
Parallelograms whose diagonals are perpendicular to each other are rhombus
sixty-nine
Property theorem of square
one
The four corners of a square are right angles and the four sides are equal
seventy
Property theorem of square
two
The two diagonals of a square are equal and equally divided vertically, each of which is divided into a group of diagonals
seventy-one
theorem
one
Two graphs about centrosymmetry are congruent
seventy-two
theorem
two
In the case of two centrosymmetric figures, the line connecting the symmetry points passes through the symmetry center and is bisected by the symmetry center
seventy-three
Inverse theorem
If the lines of the corresponding points of two graphs pass through a certain point and are connected by this point
Point bisection, then the two figures are symmetrical about this point
seventy-four
Property theorem of isosceles trapezoid
The two angles of an isosceles trapezoid on the same base are equal
seventy-five
The two diagonals of an isosceles trapezoid are equal
seventy-six
Judgement theorem of isosceles trapezoid
A trapezoid with two equal angles on the same base is an isosceles trapezoid
seventy-seven
A trapezoid with equal diagonals is an isosceles trapezoid
seventy-eight
The theorem of equal segment of parallel line
If a group of parallel lines cut on a straight line
Equal, then the line segments cut on other lines are equal
seventy-nine
inference
one
A straight line passing through the middle point of a trapezoid waist and parallel to the bottom will divide the other waist equally
eighty
inference
two
A line passing through the midpoint of one side of a triangle and parallel to the other side must be bisected
Trilateral
eighty-one
The theorem of median line of triangle
The median line of the triangle is parallel to the third side and equal to it
Half of
eighty-two
Trapezoid median line theorem
The median line of trapezoid is parallel to the two bases and equal to the sum of the two bases
half
L=
（
a+b
）
÷
2 S=L×
h
83 (1)
The basic nature of proportion
If
a:b=c:d,
that
ad=bc
If
ad=bc,
that
a:b=c:d
84 (2)
Proportional property
If
a
／
b=c
／
d,
that
(a±
b)
／
b=(c±
d)
／
d
85 (3)
Proportional property
If
a
／
b=c
／
d=… =m
／
n(b+d+… +n≠0),
that
(a+c+… +m)
／
(b+d+… +n)=a
／
b
eighty-six
The proportional theorem of parallel line segment
Three parallel lines cut two straight lines, and the corresponding result is obtained
Line segments are proportional
eighty-seven
inference
A line parallel to one side of a triangle cuts off the other sides (or extensions of both sides)
And the corresponding line segment is proportional
Theorem 88 if the corresponding line segments obtained by a straight line cutting the two sides (or the extension lines) of a triangle are proportional, then the straight line is parallel to the third side of the triangle
89 parallel to one side of the triangle and intersecting with other sides, the three sides of the triangle are proportional to the three sides of the original triangle. 90 theorem the triangle formed by a line parallel to one side of the triangle intersecting with other sides (or the extension lines of both sides) is similar to the original triangle. 91 similar triangle judgment theorem 1 the two angles are equal, Similarity of two triangles (ASA) 92 two right triangles divided by the height of the hypotenuse of a right triangle are similar to the original triangle 93 decision theorem 2 two sides are proportional and the included angle is equal, two triangles are similar (SAS) 94 decision theorem 3 three sides are proportional and two triangles are similar (SSS)
ninety-five
Theorem if the hypotenuse and one right edge of a right triangle are connected with another right triangle
If the hypotenuse of an angle is proportional to a right angle, then the two right triangles are similar. Theorem 1 the ratio of height corresponding to a similar triangle, the ratio of central line corresponding to a similar triangle and the ratio of bisector corresponding to an angle are equal to the similar ratio
97 property theorem 2 the ratio of the circumference of a similar triangle is equal to the similarity ratio 98 property theorem 3 the ratio of the area of a similar triangle is equal to the square of the similarity ratio
The sine value of any acute angle is equal to the cosine value of its cosine, and the cosine value of any acute angle is equal to the sine value of its cosine
The tangent value of any acute angle is equal to the cotangent value of its remainder, and the cotangent value of any acute angle is equal to the tangent value of its remainder
A circle is a set of points whose distance from a fixed point is equal to a fixed length
102 the interior of a circle can be regarded as a set of points whose distance from the center is less than the radius 103 the exterior of a circle can be regarded as a set of points whose distance from the center is greater than the radius
The radius of the same circle or equal circle is equal
The distance from 105 to a fixed point is equal to the track of a fixed length point, which is a circle with a fixed point as its center and a fixed length as its radius
The locus of a point whose distance from the two ends of a given line segment is equal is the vertical bisector of the line segment
107 the trajectory of a point with equal distance from both sides of a given angle is the bisector of the angle
The trajectory from 108 to the point with equal distance between two parallel lines is a straight line parallel to and with equal distance between the two parallel lines
Theorem 109 three points not on the same line determine a circle
110 vertical diameter theorem