Question

PREREQUISITE SKILL

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

84. $\frac{2}{5}b+1$

Short answer

Expression $\frac{2}{5}b+1$ results into $\frac{7}{10}$

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 $-\frac{3}{4}$for b into given expression

$\frac{2}{5}b+1=\frac{2}{5}\left(-\frac{3}{4}\right)+1$

- Simplify 25-34+1

To evaluate, firstly perform multiplication and finally addition from left to right to get

$\begin{array}{c}\frac{2}{5}\left(-\frac{3}{4}\right)+1=-\left(\frac{2\times 3}{5\times 4}\right)+1\\ =-\frac{3}{10}+1\\ =\frac{-3+10}{10}\\ =\frac{7}{10}\end{array}$

Thus, $\frac{2}{5}b+1=\frac{7}{10}$