Suppose that and . What is ?
ab = 7
a^2b + ab^2 + a + b = 80 factor
a(ab + 1) + b(ab + 1) = 80
(a + b)(ab + 1) = 80
(a+b)(7 + 1) = 80
a + b = 80/8
a + b = 10 square both sides
a^2 + 2ab + b^2 = 100
a^2 +2(7) + b^2 = 100
a^2 + 14 + b2 = 100
a^2 + b^2 = 86
