Q25. - Algebra 2

Question

Evaluate each expression if a=-5,b=6   and c=2.8

$6-\left|3c+7\right|$ 

Step-by-Step Solution

Answer

The absolute value of expression is $\mathbf{-}\mathbf{9}\mathbf{.}\mathbf{4}$

Step1- Order of evaluation

To evaluate any expression involving one operation, follow the below order of operation

• First replace the algebraic expression inside the grouping symbols like matrix brackets ( $\left|\right|$) with numeric expression
• Perform the multiplication inside the bracket

 

• Perform the addition  inside the bracket

 

• Evaluate the absolute value

 

• Perform the subtraction from left to right 

Step2- Simplify the expression inside grouping symbol

To evaluate the value of given expression, simplify the expression inside the bracket and then find the absolute value of expression as shown below

$\begin{array}{c}6-|3c+7|=6-|3\times 2.8+7|\\ =6-|8.4+7|\\ =6-\left|15.4\right|\end{array}$

Step3- Find the absolute value of expression inside the bracket and subtract

The absolute value of  $\left|15.4\right|=15.4$ 

The solution is $6-15.4=-9.4$.