Given a + B-8A + 6B + 25 = 0, find the solution of a + B of a-4ab + 4B

Given a + B-8A + 6B + 25 = 0, find the solution of a + B of a-4ab + 4B

Because a ^ 2 + B ^ 2-8a + 6B + 25 = 0,
So (a ^ 2-8a + 16) + (b ^ 2 + 6B + 9) = 0,
So (A-4) ^ 2 + (B + 3) ^ 2 = 0,
So A-4 = 0, B + 3 = 0,
So a = 4, B = - 3,
So (a ^ 2 + B ^ 2) / (a ^ 2-4ab + 4B ^ 2)
=[4^2+(-3)^2]/[4-(-3)]^2
=25/49.