Question

In the following exercises, evaluate each expression.

${\left(y+z\right)}^2$when $y=-3$ and$z=15$

Short answer

The value is 144.

Step-by-step solution

Step 1. Given Information:

The given expression is ${\left(y+z\right)}^2$and the value of the variables are $y=-3$and $z=15$.

Step 2. Substitute the values: 

Substitute $-3$for $y$and 15 for $z$into the given expression, ${\left(y+z\right)}^2$.

${\left(\left(-3\right)+15\right)}^2$

Step 3. Perform Addition.

Add $-3$and 15 inside the parentheses.

role="math" localid="1644671739723" ${\left(\left(-3\right)+15\right)}^2={\left(12\right)}^2$

Step 4. Calculate the exponent.

Calculate the exponent using the definition of exponential notation, $a^n=\underset{nfactors}{\underbrace{a·a·\cdots ·a}}$.

$\begin{array}{rcl}{\left(12\right)}^2& =& \left(12\right)\left(12\right)\\ & =& 144\end{array}$

Step 5. Conclusion:

The value obtained is 144.