Aunt Zhang has 14 pieces of RMB 5 yuan and 10 yuan, just 100 yuan. How many pieces of RMB 5 yuan and 10 yuan? How to solve the equation

Aunt Zhang has 14 pieces of RMB 5 yuan and 10 yuan, just 100 yuan. How many pieces of RMB 5 yuan and 10 yuan? How to solve the equation

The equation of one variable is: let 5-variable x-sheet, 5x + 10 (14-x) = 100, x = 8
The binary equation is, let X of 5 and y of 10
X+Y=14
5X+10Y=100
The solution is: x = 8, y = 6

Aunt Zhang has 14 pieces of RMB 5 yuan and 10 yuan, which is exactly 100 yuan. How many pieces of RMB 5 yuan and 10 yuan

What about the title?

Uncle Li has four kinds of RMB: 5 yuan, 10 yuan, 20 yuan and 50 yuan, totaling 3400 yuan
Be right

There are x sheets for each
5X+10X+20X+50X=3400
85X=3400
X=3400/85
X=40
There are 40 each

Po is perpendicular to the plane, O is the perpendicular foot, PA and Pb are the oblique lines of the plane, and a and B are the oblique feet?

Angle AOB > angle APB. Because angle AOB is the projection of angle APB on the plane

Factorization factor X3 + 5x2 + 8x + 4

Original = (X & # 179; + X & # 178;) + (4x & # 178; + 8x + 4)
=x²(x+1)+4(x+1)²
=(x+1)(x²+4x+4)
=(x+1)(x+2)²

How to calculate the diagonal of parallelogram

First know the angle between the two sides. Then use the cosine theorem
C2 = A2 + B2 + 2Ab * cos angle
C is the diagonal, a and B are the adjacent sides of the parallelogram

Solution equation: 4 / X-5 + X-5 / 12-x = X-33 / x ^ 2-17x + 60
thx```````

4 / (X-5) - (X-5) / (X-12) = (X-33) / (X-5) (X-12) multiply both sides by (X-5) (X-12) 4 (X-12) - (X-5) ^ 2 = x-33x ^ 2-10x + 25-4x + 48 + X-33 = 0x ^ 2-13x + 40 = 0 (X-5) (X-8) = 0x = 5, x = 8. The fractional equation needs to be tested, x = 5 makes the denominator zero, so x = 8

Through the point P (0, - 8) to the circle X & # 178; + Y & # 178; + 2x-4y = 0, the tangent line is drawn and the tangent length is calculated

Circle X & # 178; + Y & # 178; + 2x-4y = 0
(x+1)²+(y-2)²=5
The circle with O (- 1,2) as the center and √ 5 as the radius
The tangent point, P and the center of the circle form a right triangle
OP = √[1²+(-8-2)²] = √101
Tangent & # 178; = OP & # 178; - R & # 178; = 101-5 = 96
Tangent = √ 96 = 4 √ 6

A hope school has received 65 new year gifts from various sponsors. It plans to get the same number of New Year gifts for each class, but the result is still 3. If each class gets one less gift, the result is 14. How many classes does the hope school have?
First floor, you can do it. Can you make the equation for me

There are x classes, and Y pieces are allocated for each class for the first time
Simultaneous xy = 65 + 3 (1)
x(y-1)=65-14(2)
Bring (1) as a whole into (2)
Xy-x = 65-14 then 68-x = 51
Then x = 17

Let set a = {X-Y, x + y, XY}, B = {x2 + Y2, x2-y2, 0}, and a ⊆ B, B ⊆ a, find the value of real number x, y and set a, B

A ⊆ B ⊆ B, B ⊆ a, B B ⊆ a, B \8838; B 88388838; a = B, a = {X-Y, x + y (x + y, x + y, x + X + y, x + y, x + y, X 88383838b B B 8838383838383838b \\\\\\\\\\\\\\\\\\\\\\\\\\\\ify = 1 or Y = - 1, when y = 0, the set When y = 1, the set a = {- 1, 1, 0}, B = {1, - 1, 0}, satisfies the condition, then x = 0, y = 1. When y = - 1, the set a = {- 1, 1, 0}, B = {1, - 1, 0}, satisfies the condition, then x = 0, y = - 1. When y = 0, the set a = {x, x, 0}, B = {X2, X2, 0}, does not hold. To sum up, x = 0, y = - 1, the corresponding set a = {- 1, 1, 0}, B = {1, - 1, 0}