Question

can someone do these two questions.

Answer 1

a+b)(a-b) =a^2-b^2

15p^2-12q^2
=225p^2-144q^2

Answer 2

a+b=25
a^2 +b^2 =225
so eq . a+b=25
Square on Lhs and Rhs
(a+b)^2=(25)^2
a^2+b^2+2ab=625
put in the value of a^2+b^2
225+ 2ab=625
2ab=625-225
2ab=400
ab=200