Find the values of a^2 + b^2 and a^4 + b^4 when a + b =5 and Ab = 4

Answer 1

b = 4/a

a + 4/a = 5

a^2 - 5 a + 4 = 0

(a-4)(a-1) = 0
a = 1 or a = 4
if a = 1 then b = 4 etc

1 + 16 = 17

1 + 256 = 257