Question

Evaluate the expression when $x=6\text{and}y=12$. (Lesson 1.3)

localid="1649147454754" $5x-y$

Short answer

The value of the expression is18.

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 – Multiply from left to right

To evaluate the expression $5x-y$, substitute 6 for x and 12 for y in the given expression and simplify further as shown below

$\begin{array}{c}5x-y=5\cdot 6-12\\ =30-12\end{array}$

Step-3 – Subtract the numbers

Now to simplify further, subtract the numbers to get

$\begin{array}{c}5x-y=30-12\\ =18\end{array}$

Thus, the value of the expression is 18.