Q63. - Algebra 1

Question

Evaluate each expression. (Lesson 1-2)

${\left(-9\right)}^2$

Step-by-Step Solution

Answer

The solution is 81.

Step 1. State the formula.

For any real number $a$, $a^2=a\times a$. Moreover, $\left(-1\right)\times \left(-1\right)=1$.

Step 2. List the given objective.

To evaluate ${\left(-9\right)}^2$.

Step 3. Evaluate the expression.

Put $a=-9$ in $a^2=a\times a$ to get,

$\begin{array}{l}{\left(-9\right)}^2=\left(-9\right)\times \left(-9\right)\\ =\left(-1\right)\times \left(-1\right)\times 81\\ =81\end{array}$

So, ${\left(-9\right)}^2=81$.