According to the order of operations, expressions inside parentheses and other grouping symbols are evaluated first, while addition and subtraction are evaluated last. For the given expression, this means evaluating the expression inside parentheses completely before evaluating the resulting expression inside square brackets.
3[42-2(10^2-9^2)]Notice also that even within this parenthetical expression, we must obey the order of operations.
10^2-9^2
For this, we must remember to evaluate the exponent first, and the difference between their results next.
Operation
Before Simplification
After Simplification
Calculate power
3[42-2( 10^2- 9^2)]
3[42-2( 100- 81)]
Subtract term
3[42-2( 100- 81)]
3[42-2( 19)]
Multiply
3[42- 2( 19)]
3[42- 38]
Subtract term
3[ 42- 38]
3[ 4]
Multiply
3[ 4]
12
The expression equals 12.
Alternative Solution
Using a Calculator
We can also evaluate this expression using a calculator. To do so, type it as shown below.
