If the two solutions of the equation MX + NY = 6 are x = 1y = 1, x = 2Y = − 1, then the value of M, n is () A. 4，2B. 2，4C. -4，-2D. -2，-4

If the two solutions of the equation MX + NY = 6 are x = 1y = 1, x = 2Y = − 1, then the value of M, n is () A. 4，2B. 2，4C. -4，-2D. -2，-4

Substituting x = 1y = 1, x = 2Y = − 1 into MX + NY = 6, we get m + n = 6, ① 2m − n = 6, ②, ① + ② get 3M = 12, that is, M = 4, substituting M = 4 into ① get n = 2, so we choose: a

If x = 2Y = - 5 and x = 1y = - 1 are two solutions of the equation MX + NY + 15, find the value of M and n

Substitute these two sets of values into the equation MX + NY = 15
X = 2Y = ― 5 into 2m-5n = 15 ①
X = 1y = ― 1 substituting M-N = 15 ②
The solution (1, 2) is n = 5 and then M = 20 by using (2 * 2 - 1)

The solution of equation 1 / 3x-6 = 3 / 4x-8 is ()
A.2 B.3 C.4 D.

D

Solution equation: 17 times 0.5-3x = 2.5

17 times 0.5-3x = 2.5
8.5-3x=2.5
3x=8.5-2.5
3x=6
x=6÷3
x=2

Given that the solutions of the equations 4x 10 2m 2 3x 10 2M and 3x 10 2m = 6x 10 1 are the same, the value of M is obtained

The first equation shows that x = 0
Take the second one to get m = 1 / 2

How to use cross multiplication to solve 3x & # 178; - 8x-9 = 0?

This equation can not be solved by cross multiplication, the solution of this equation is not an integer, and not all quadratic equations of one variable can be solved by cross multiplication

Solving equation-x ^ 2-3x + 10 = 0 6x ^ 2 + X-1 = 0 by cross phase multiplication
-X^2-3X+10=0 6X^2+X-1=0 4X^2+24X+27=0 3X^2-7X-6=O4X^2-4X-15=0 20-9X-20X^2=0 （X+3）^2+5(X+3)-6=0

-X2-3x + 10 = 0 (x + 2) (X-5) = 0, x = - 2 or 56x2 + X-1 = 0, x = 1 / 3 or 1 / 2

Cross phase multiplication factorization, 2x ^ 2-3x + 1, 6x ^ 2 + 5x-6

1 -1
×
2 -1
Original formula = (x-1) (2x-1)
3 -2
×
2 3
Original formula = (3x-2) (2x + 3)

3x ^ 2-18x + 27 cross multiplication factorization

(3x-9)(x-3)

(1) X & sup2; - 2 (2) 2x & sup2; - 7x-4 (3) x & sup2; + X-2 (4) 2x & sup2; - 3x + 1 solve the equation by cross phase multiplication
(1)（x-2）²

(1)x²-2
=(x-√2)(x+√2)
(x-2)^2=x^2-4x+4
（2）2x²-7x-4
=(2x+1)(x-4)
（3）x²+x-2
=(x+2)(x-1)
（4）2x²-3x+1
=(2x-1)(x-1)