Question

PREREQUISITE SKILL

Evaluate each expression if $a=2,b=-\frac{3}{4},$and c=1.8.

86. $-9\left(a-6\right)$

Short answer

Expression $-9\left(a-6\right)$ results into 36

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.

- Substitute given values

Substitute 2 for a into given expression

$-9\left(a-6\right)=-9\left(2-6\right)$

- Simplify -92-6

To evaluate, firstly simplify parentheses then perform multiplication as shown below

$\begin{array}{c}-9\left(2-6\right)=-9\left(-4\right)\\ =36\end{array}$

Thus, $-9\left(a-6\right)=36$