1)y=(x^3-2)(2x^3+1) 2)y=x^2 (x-3) 3)y=x^3 (3x+2) 4)y=(3x^2-4)(7x^2+x-1) !

1)y=(x^3-2)(2x^3+1)
y=2x^6+x^3-4x^3-2
y=2x^6-3x^3-2
2)y=x^2(x-3)
y=x^3-3x^2
3)y=x^3 (3x+2)
y=3x^4+2x^3
4)y=(3x^2-4)(7x^2+x-1)
y=21x^4+3x^3-3x^2-28x^2-4x+4
y=21x^4+3x^3-31x^2-4x+4