Question

If f(x)=(-x)^3-x^2-x+15What would f(-5) = to?

Answer 1

Given the equation:

`f(x)=(-x)^3-x^2-x+15`

To find f(-5), substitute x by -5 and solve the equation.

`f(-5)=[-(-5)\rbrack^3-(-5)^2-(-5)+15`

To solve it, first, solve the signs and the exponents.

`\begin{gathered} f(-5)=5^3-(-5)^2+5+15 \\ f(-5)=125-25+20 \\ f(-5)=120 \end{gathered}`

Answer: f(-5) = 120.