Question

How do you evaluate $-7^2$?

Answer 1

Evaluating the required expression.

As we know, the value of a number raised to the power of $2$ is called its square.

If we square a negative number, it becomes positive. Because the product of two negative numbers is always positive.

If we find square of a negative number, $-x$, here $x>0$, then,

$\Rightarrow$ $\left(-x\right)\times \left(-x\right)=x^2$

Here, $x^2>0$.

So,

$\Rightarrow$ $-7^2=\left(-7\right)\times \left(-7\right)$

$\Rightarrow$ $-7^2=49$

Hence, the value of $-7^2$ is $49$.