Question

Giúp em vs em cần gấp ạ !!!

Answer 1

Lời giải:
a. $(x^2-1)(x^2+2x)=x^4+2x^3-x^2-2x$

b. $(2x-1)(3x+2)(3-x)=(6x^2+4x-3x-2)(3-x)$

$=(6x^2+x-2)(3-x)=18x^2-6x^3+3x-x^2-6+2x$

$=-6x^3+17x^2+5x-6$

c.

$(x+3)(x^2+3x-5)=x^3+3x^2-5x+3x^2+9x-15$

$=x^3+6x^2+4x-15$

d.

$(x+1)(x^2-x+1)=x^3+1^3=x^3+1$

e.

$(2x^3-3x-1)(5x+2)=10x^4+4x^3-15x^2-6x-5x-2$

$=10x^4+4x^3-15x^2-11x-2$

f.

$(x^2-2x+3)(x-4)=x^3-4x^2-2x^2+8x+3x-12$

$=x^3-6x^2+11x-12$