Chapter 6, Problem 1RE

In Exercises 1–4, evaluate the expression for the given value(s) of the variable.

1. x² + l0x,   x = 3

To determine

To evaluate: The expression for the given value of the variable.

Answer to Problem 1RE

The value of the expression $x^2+10x$ at $x=3$ is 39.

Explanation of Solution

Given:

The expression is $x^2+10x$ at $x=3$.

Calculation:

Obtain the value of the expression $x^2+10x$.

Substitute $x=3$ in $x^2+10x$,

$\begin{array}{c}{x}^2+10x={\left(3\right)}^2+10\left(3\right)\\ =\left(3\times 3\right)+\left(10\times 3\right)\\ =9+30\\ =39\end{array}$

Therefore, the value of the expression $x^2+10x$ at $x=3$ is 39.