So I need help with this problem, I’m new to polynomials. Can you also explain how to get the answer?
Find the polynomial that models the problem and use it to estimate the quantity:
A rectangle has a length of $x$ and a width of $5x^3 + 4 - x^2$. Find the perimeter of the rectangle when the length is 5 feet.
The perimeter of a rectangle is $2($length$+$width$)$. Put the values of length and width. You'll get : Perimeter$=2×(x+5x^3+4-x^2)$. That's the polynomial of perimeter. Now put $x=5$, since the length$=5$. You'll get $2×(5+5×5^3+4-5^2) = 1218$. That's the required perimeter.