Question

If a-b=10 and ab=2 then a2+b2

Answer 1

a-b=10 (given)
squaring both the sides
(a-b)^2=100
a2+ b2-2ab=100
a2+b2=100+2ab
a2+b2=100+2*2 [ab=2] given
a2+b2=104