Question

Can someone please help me with this question? I don't know how? What is the volume of a rectangular prism with a length of 2x – 1, a width of x – 2, and a height of x + 1? 4x3 – 2 2x3 – x2 – 2x + 2 2x3 + 3x2 + 3x + 2 2x3 – 3x2 – 3x + 2

Answer 1

volume is legnth times widht times height
lenght=2x-1
width=x-2
height=x+1
multiply all together
use mass distributive property
distributive=a(b+c)=ab+ac so extending that
(a+c)(c+c)=(a+b)(c)+(a+b)(d) then keep distributing so
(2x-1)(x-2)(x+1)
do each one seperately
do the first two first and put the other one (x+1) to the side for later
(2x-1)(x-2)=(2x-1)(x)+(2x-1)(-2)=(2x^2-x)+(-4x+2)=2x^2-5x+2
then do the other one
(x+1)(2x^2-5x+2)=(x)(2x^2-5x+2)+(1)(2x^2-5x+2)=(2x^3-5x^2+2x)+(2x^2-5x+2)=2x^3-3x^2-3x+2

the lasst form is 2x^3-3x^2-3x+2