Answer:
(5a+8)/(a+b) = x
Explanation:
a(5-x) = bx -8
Distribute
5a -ax = bx -8
Add ax to each side
5a -ax +ax = bx+ax -8
5a = bx+ax -8
Add 8 to each side
5a +8 = ax+bx -8+8
5a +8 = ax+bx
Factor out the x
5a+8 = x(a+b)
Divide each side by (a+b)
(5a+8)/(a+b) = x(a+b)/(a+b)
(5a+8)/(a+b) = x