Question

хелп решите:)))))))))))

Answer 1

3x (x - y) + 3y(x + y) = 
= 3x^2 - 3xy + 3yx + 3y^2 = 
= 3x^2 + 3y^2 = 
= 3(x^2 + y^2)

Answer 2

3х(х-у)+3у(х-у)=
=(3х+3у)(х-у)=
=3(х+у)(х-у)=
=3(х^2-у^2)=
=3х^2-3у^2