It is known that 3x ^ (a + 5b-5) - 2Y ^ (3a-6b-3) = 5 is a quadratic equation with respect to X and y, and the value of a + 2b is obtained

It is known that 3x ^ (a + 5b-5) - 2Y ^ (3a-6b-3) = 5 is a quadratic equation with respect to X and y, and the value of a + 2b is obtained

3x ^ (3a-6b-3) - 2Y ^ (a + 5b-5) = 5 is a quadratic equation of two variables
So 3a-6b-3 = 1
a+5b-5=1
A = 8 / 3, B = 2 / 3 are obtained from the joint equation
So a + 2B = 8 / 3 + 4 / 3 = 4

If a bamboo pole is less than 6 meters long, measure it from one end to 3 meters and make a mark a, then measure it from one end to 3 meters and make a mark B. at this time, the distance between AB is 20% of the total length, then the length of the bamboo pole is______ Rice

(3 + 3) / (1 + 20%) = 6 / 120%, = 5 (m); answer: the length of bamboo pole is 5 m

In a rational number, what is the number whose opposite number equals itself

On the contrary, the number equal to itself has (0);

The Institute of Agricultural Sciences recommended Yujiang I and Yujiang II to farmers

Under the condition of the same field management and soil quality, the yield per unit area of No.2 rice is 20% lower than that of No.1 rice, but the quality of No.2 rice is better and the price is higher than that of No.1 rice. It is known that the national purchase price of No.1 rice is 1.6 yuan / kg
(1) When the national purchase price of rice No.2 is what, the income of rice No.1 and rice No.2 will be the same if they are planted in two fields with the same field management, soil quality and area?
(2) Last year, Xiao Wang planted rice No.1 and No.2 in two fields with the same soil and area, and carried out the same field management. After harvest, Xiao Wang sold all the rice to the state. When he sold the rice to the state, the national purchase price of No.2 rice was set at 2.2 yuan / kg. The purchase price of No.1 rice remained unchanged, so Xiao Wang No.2 rice earned 1040 yuan more than No.1 rice, How many kilograms of rice did Xiao Wang sell to the state last year?
(1) , number one, number two
Yield: 1,1-20%
Price: 1.6 yuan,
Suppose that the purchase price of rice No. 2 is x yuan,
Then: 1.6 * 1 = x * (1-20%)
0.8x=1.6
x=2
(2) Suppose the yield of rice No.1 is x kg, and that of rice No.2 is x (1-20%) = 0.8x
1.6X+1040=2.2*0.8X
1.6x+1040=1.76x
0.16x=1040
x=6500
The yield of No.2 rice is 0.8 * 6500 = 5200
As a result, Xiao Wang sold state rice last year: 6500 + 5200 = 11700 kg
151 | comments (11)

Given that the radius of circle O is 15, the chord PQ ‖ Mn, and PQ = 18, Mn = 24, find the distance between the two chords PQ and Mn

Ab ⊥ PQ is done through the center O, PQ is intersected with a, Mn is intersected with B ∵ PQ ∥ Mn ≁ ab ⊥ Mn ≁ according to the vertical meridian theorem: AP = AQ = 1 / 2pq = 9bm = BN = 1 / 2Mn = 12, Op, Op = om = 15 ≁ according to the Pythagorean theorem: OA ≁ 178; = op ≁ 178; - AP ≁ 178; = 15 ≁ 178; - 9 ≁ 178; = 12 ≁ 178;, OA = 12ob ≁ 178; = om ≁ 178; -

1.x（x-4）+2（4-x）=0
2.（3x-1）^2=（x-3）^2

One
x(x-4)-2(x-4)=0
(x-2)(x-4)=0
So x = 2 or x = 4
two
(3x-1)^2-(x-3)^2=0
(3x-1+x-3)(3x-1-x+3)=0
(4x-4)(2x+2)=0
(x-1)(x+1)=0
So x = 1 or x = - 1

Find the trajectory equation of the intersection point P of two tangent lines of a circle!
Through the circle x2 + y2 = R2, a point m (a, b) acts the chord ab. through a and B, the tangent of the circle is made respectively, and the trajectory equation of the intersection point P of the two tangent lines is obtained
Do you understand the first floor? Circle is a fixed circle, M is a fixed point, you can find a p to see if it can meet the meaning of the problem?
The second floor is also wrong. It's impossible to work out the AB coordinates. The coordinates of analytic geometry are generally set but not worked out
The AB coordinate can't be found here

In fact, it's not difficult, because there are too many letters. It's too troublesome. The general process is to first solve the equation passing through point m, then work out the coordinates of a, B and the circle equation, and then work out the trajectory equation of two straight lines passing through point a and point B respectively and perpendicular to chord a and B. after working out the intersection point, the value obtained is the trajectory equation of P

F (x) is a function defined on R, m and N belong to R, and f (m) * f (n) = f (M + n)
(1) Prove that f (0) = 1;
(2) When x > 0, 0

1.
When m = 0, n = 0, substitute f (m) * f (n) = f (M + n). There is f (0) * f (0) = f (0). Therefore, f (0) = 0 or 1
When m = 1, n = 0, substitute f (m) * f (n) = f (M + n). There is f (1) * f (0) = f (1). Therefore, f (0) ≠ 0
So we prove that f (0) = 1
two
If x > 0, - x1
When m = x, n = - x, substitute f (m) * f (n) = f (M + n). F (x) * f (- x) = f (0) = 1
So 0

The PA ⊥ plane ABCD is known, and the quadrilateral ABCD is a rectangle, m and N are the midpoint of AB and PC respectively. The verification is: (1) Mn ⊥ plane pad; (2) Mn ⊥ CD; (3) Mn ⊥ plane PCD when ∠ PDA = 45 °

(1) It is proved that: ∵ the quadrilateral ABCD is a rectangle, m and N are the midpoint of AB and PC respectively, and then take the midpoint Q of PD and connect NQ, then there is NQ ∥ 12CD, and NQ = 12CD. Similarly, we can get Ma ∥ 12CD, and Ma = 12CD. ∥ NQ ∥ Ma, NQ = ma. & nbsp; so the quadrilateral mnqa is a parallelogram, ∥ Mn ∥ PQ

It is known that the maximum value of F (x) = cos's Square x plus 2 asinx-a is g (a). The analytic expression of G (a) and its minimum value are obtained
Need complete steps to solve the problem

F (x) = cos & sup2; X + 2asinx-a = 1-sin & sup2; X + 2asinx-a = - (Sin & sup2; x-2asinx + A & sup2;) + A & sup2; - A + 1 = - (sinx-a) & sup2; + A & sup2; - A + 1 when A1, when SiNx = 1, f (x) is the largest, then G (a) = a; when A3, when - 1 ≤ a ≤ 1, G (a) = A & sup2; - A + 1 = (a-0.5) & su