Question

4(3x+4y)^2-7(2x-3y)^2

 

 

Answer 1

$4(3x+4y)^2-7(2x-3y)^2=\\4(9x^2+24xy+16y^2)-7(4x^2-12xy+9y^2)=\\36x^2+96xy+64y^2-28x^2+84xy-63y^2=8x^2+180xy+y^2$