Question

$if \: a + b = 8 and \: ab = 15 \: find \: a ^{2} + b^{2}$

Answer 1

a+b=8
squaring both sides,
a^2 + b^2 + 2ab = 64
a^2 + b^2 = 64 - 30 = 34

Answer 2

Answer is in Attachment !