Answer:
[tex]x^{4}[/tex] + 3x³ - 3x - 1
Step-by-step explanation:
The area (A) of a rectangle is calculated as
A = lw ( l is the length and w the width ) , thus
A = (3x² - 2x - 1)(x² + x + 1)
Each term in the second factor is multiplied by each term in the first factor, then
A = 3x²(x² + x + 1) - 2x(x² + x + 1) - 1(x² + x + 1) ← distribute parenthesis
= 3[tex]x^{4}[/tex] + 3x³ + 3x² - 2[tex]x^{4}[/tex] - 2x² - 2x - x² - x - 1 ← collect like terms
= [tex]x^{4}[/tex] + 3x³ - 3x - 1