Question

Evaluate each expression if $a=4,b=3$and $c=9$.

$c+3a$

Short answer

The value of the given expression is $21$.

Step-by-step solution

Step 1. Method of applying order of operations.

1. Evaluate expressions inside grouping symbols
2. Evaluate all powers.
3. Multiply and/or divide in order from left to right
4. Add or subtract in order from left to write.

Step 2. Putting the values of given variables in the expression.

$c+3a=9+3·4\left[\mathrm{since}a=4,c=9\right]$

Step 3. Simplifying the expression.

$$\begin{gathered} 9+3·4=9+12\left[\mathrm{Performing}\mathrm{multiplication}\right] \\ =21\left[\mathrm{Performing}\mathrm{addition}\right] \end{gathered}$$