A= x(x+6)-x
= x^2+6x-x
= x^2+5x
B= x(y-2)+xy
= xy-2x+xy
= 2xy-2x
C= 3x(x+4)-6x^2
= 3x^2+12x-6x^2
= -3x^2+12x
D= 9x(x^2-6)+2x^2
= 9x^3-54x+2x^2
E= 5x(3+5x)+x(5+x)+4x(2x+1)
= 15x+25x^2+5x+x^2+8x^2+4x
= 34x^2+24x
F= 7x(3x-5)-6x(8+7x)
= 21x^2-35x-48x-42x^2
= -21x^2-83x
G= 9(3+9x)+4x^2(7-12x)-11x(-5+8)
= 27+81x+28x^2-48x^3+55x-88x
= -48x^3+28x^2+48x+27
