If x = 1, y = 6 and x = - 3, y = - 4 are solutions of the equation AX + by + 7 = 0, try to judge whether x = 3, y = 11 are solutions of the equation AX + by + 7 = 0

If x = 1, y = 6 and x = - 3, y = - 4 are solutions of the equation AX + by + 7 = 0, try to judge whether x = 3, y = 11 are solutions of the equation AX + by + 7 = 0

Because x = 1y = 6
So a + 6B = - 7 1
Because x = - 3Y = - 4
So - 3a-4b = - 7 2
Composition equations
A = - 1B = - 1
Take a = - 1, B = - 1, x = 3, y = 11 into ax + by + 7 = 0
-3-11 + 7 = 0 is wrong, so x = 3, y = 11 is not the solution of AX + by + 7 = 0