Question

Evaluate the expression $5\left(21-3^2\right)$.

Short answer

The value of expression is60.

Step-by-step solution

Step-1 – Order of operations

To evaluate any expression involving more than one operation, follow the below order of operations:

• First evaluate expressions inside grouping symbols like parentheses ( ) or brackets [ ].
• Evaluate the exponents.
• Perform Multiplication and division from left to right.
• Perform addition and subtraction from left to right.

Step-2 – Simplify expression in grouping symbol

The expression is provided as $5\left(21-3^2\right)$

To evaluate the expression, expand the exponent and then subtract the resulting number from 21 as shown

$\begin{array}{c}5(21-3^2)=5(21-9)\\ =5\left(12\right)\end{array}$

Step-3 – Multiply the numbers

To simplify further, multiply the resulting numbers to get

$\begin{array}{c}5(21-3^2)=5\left(12\right)\\ =60\end{array}$

So, the value of the expression is 60.