Question

Find the value of the polynomial $3x^3-4x^2+7x-5$ when $x=-3$.

Answer 1

Substitute the value of $x=-3$ in the given equation.

The given equation is $3x^3-4x^2+7x-5$.

Substituting $x=-3$ in the above equation,

$$\begin{gathered} \Rightarrow 3{\left(-3\right)}^3-4{\left(-3\right)}^2+7\left(-3\right)-5 \\ =3\left(-27\right)-4\left(9\right)-21-5 \\ =-81-36-21-5 \\ =-143 \end{gathered}$$

Hence, the value of $3x^3-4x^2+7x-5$ when $x=-3$. is $-143$.