If the solution of the system ax + 2Y = b4x − by = 2A − 1 is x = 1y = − 1, then a=______ ，b=______ ．

If the solution of the system ax + 2Y = b4x − by = 2A − 1 is x = 1y = − 1, then a=______ ，b=______ ．

Substituting x = 1, y = - 1 into the equations, we get a − 2 = B ① 4 + B = 2A − 1 ②, and the solution is a = 3, B = 1

It is known that the image of quadratic function y = x2 + BX + C has two intersections with X axis, and the equation of symmetry axis of function is X=
Find: (1) the value of B, C, (2) if f (x) is not greater than 7, find the value range of X
The axis of symmetry equation x = 2, and f (x) has a minimum value of - 9

From the equation x = - B / 2a, and a = 1, the solution is: 2 = - B / 2, that is, B = - 4
Substituting x = 2, f (x) = - 9 into y = x2 + BX + C, we get - 9 = 4 + 2B + C, and the solution is C = - 5
So the quadratic function y = x2 + BX + C is y = x & # 178; - 4x-5
（1）b=-4；c=-5.
(2) If f (x) is not greater than 7, find the value range of X
x²-4x-5≤7
x²-4x-12≤0
(x-6)(x+2)≤0
If (X-6) ≤ 0 and (x + 2) ≥ 0, then - 2 ≤ x ≤ 6
Or (X-6) ≥ 0, (x + 2) ≤ 0, no solution
So the value range of X is - 2 ≤ x ≤ 6

Learn a linear equation of one variable, which meets the following conditions: 1. The solution of the equation is x = 2; 2. The coefficient of the unknown x is - 3?

Solution - 3x = 6