It is known that x = 1 is a solution of the quadratic equation AX 2 + bx-40 = 0, and a ≠ B. find (a minus b) divided by (2a-2b)

It is known that x = 1 is a solution of the quadratic equation AX 2 + bx-40 = 0, and a ≠ B. find (a minus b) divided by (2a-2b)

Substituting x = 1 into the equation yields
a+b-40=0
a+b=40
(a^2-b^2)/(2a-2b)
=(a+b)(a-b)/2(a-b)
=(a+b)/2
=40/2
=20