Question

X-y = 10 x^2-y^2 = 60 x^2+2xy+y^2=?

Answer 1

 

$\displaystyle\\x-y=\boxed{10}\\\\----------\\\\x^2-y^2 = 60\\\\(x-y)(x+y)=60\\\\10(x+y)=60\\\\x+y=\frac{60}{10}=\boxed{6}\\\\----------\\\\x^2+2xy+y^2=(x+y)^2=6^2=\boxed{\bf36}$