Question

Evaluate the expression when $r=4\text{and}s=6$.

localid="1649074157352" $2\left(r^2-15\right)$

Short answer

The value of the expression is2.

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 – Evaluate the expression inside parenthesis

To evaluate the expression $2\left(r^2-15\right)$, substitute 4 for r and 6 for s in the expression and then simplify further by evaluating the expression in parenthesis as shown below,

$\begin{array}{c}2(r^2-15)=2(4^2-15)\\ =2(16-15)\\ =2\left(1\right)\end{array}$

Step-3 – Multiply the numbers

Now to simplify further, remove the parenthesis and multiply the numbers as shown below.

$\begin{array}{c}2(r^2-15)=2\left(1\right)\\ =2\end{array}$

Thus, the value of the expression is 2.