Question

Find the value of each expression

12. $\left[21-\left(9-2\right)\right]÷2$

Short answer

Expression $\left[21-\left(9-2\right)\right]÷2$ results into 7.

Step-by-step solution

- Order for simplification 

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.

- Simplify grouping expression

To evaluate given expression, first simplify parentheses and then bracket as shown below:

$\begin{array}{c}\left[21-\left(9-2\right)\right]÷2=\left[21-7\right]÷2\\ =14÷2\end{array}$

– Divide 14 by 2

To simplify further, divide the terms from left to right.

$14÷2=7$