Question

Answer 1

1.

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

$=6x+4=6.\frac{-10}{3}+4=-16$

2.

$6x(2x-7)-(3x-5)(4x+7)=(12x^2-42x)-(12x^2+x-35)$

$=-42x-x+35=-43x+35=-43(-2)+35=121$

 

Answer 2

3.

$(x-3)(x+3)-(x+2)(x-1)=(x^2-9)-(x^2+x-2)$

$=-9-x+2=-7-x=-(7+\frac{1}{3})=\frac{-22}{3}$

4.

$x^3-9x^2+27x-27=(x-3)^3=(5-3)^3=8$