Question

[1.5x-4y][1.5x+4y+3]-4.5x+12y

 

Answer 1

=1.5*1.5*x*x+1.5*4*x*y+3*1.5-4*1.5*x*y-4*4*y*y-12y-4.5x+12y
so
=2.25x*x-16y*y+4.5x-4.5x+12y-12y+4*1.5*x*y-4*1.5*x*y
so
=2.25*x*x-16*y*y