Question

Can someone help me with this? My teacher said its a must in the homework and i cant find a solution.

Answer 1

Answer:

$8x^3+28x^2-16x$

Step-by-step explanation:

Volume of rectangular prism: $l*b*h$ (l = length, b = breadth, h = height.)

Volume of rectangular prism:

$(x+4)*(2x-1)*4x$

$4x\left(x+4\right)\left(2x-1\right)$

Expand the two brackets using FOIL:

$4x(x* \:2x+x\left(-1\right)+4* \:2x+4\left(-1\right))$

$4x\left(2x^2+7x-4\right)$

Expand:

$4x* \:2x^2+4x* \:7x+4x\left(-4\right)$

$8x^3+28x^2-16x$