Find the values of a^2 + b^2 and a^4 + b^4 when a + b =5 and Ab = 4
recall that
(a+b)^2 = a^2 + b^2 + 2ab
so
5^2 = a^2 + b^2 + 2(4)
a^2 + b^2 = 25-8 =17
similarly
(a+b)^4 = a^4 + 4a^3b + 6a^2b^2 + 4ab^3 + b^4
5^4 = (a^4 + b^4) +4ab(a^2 + b2) + 6(ab)^2
625 = (a^4 + b^4) + 4(4)(17) + 6(4^2)
take over