Question

Tính:

a, \(\left(x-1\right)\left(x+1\right)\left(x+2\right)\)

b, \(\frac{1}{2}x^2y^2\left(2x+y\right)\left(2x-y\right)\)

Answer 1

a) (x-1)(x+1)(x+2)=(x²-1)(x+2)=x³+2x²-x-2

b) \(\frac{1}{2}x^2y^2\left(2x+y\right)\left(2x-y\right)\)

=\(\frac{1}{2}x^2y^2\left(4x^2-y^2\right)\)

=\(2x^4y^2-\frac{1}{2}x^2y^4.\)

Answer 2

a, (x-1)(x+1)(x+2)
= (x^2-1)(x+2)
=x^3+2x^2-x-2
b,1/2x^2y^2(2x+y)(2x-y)
=1/2x^2y^2(4x^2-y^2)
=2x^4y^2-1/2x^2y^4