Question

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

localid="1649147484508" $3x+y$

Short answer

The value of the expression is30.

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 $3x+y$, substitute 6 for x and 12 for y in the given expression and simplify further as shown below

$\begin{array}{c}3x+y=3\cdot 6+12\\ =18+12\end{array}$

Step-3 – Add the numbers

Now to simplify further, add the numbers to get

$\begin{array}{c}3x+y=18+12\\ =30\end{array}$

Thus, the value of the expression is 30.