a) 16x³y³: (-4xy²)+(-2x²yX-7y²)+ 12x²y³ = b) ala² +3a-2)+(a− 2)(a + 3)-2= c) (2x+3)(3-x)+(1-x)(1+x)= d) (a-7)(2a +1)+(a−2)² = e) (3a-1)-a²+(a+3)² = (a-5)(a +6)-(a-3)²-3a(a-1)= (a+3)(a-3)+(2a-1)(3a+5)= g) h) (x-2y)² + (y-3x)²-(y-x)y+x(2y + 3x)= i) 3x(x-a)²+(a + 3x)².x = j) (5x-2y)(5x+2y)-(3x-y)(x-2y)=
