We know that
- $8 is the base price
- $2.50 "PER" pound
The more weight there is the more it will cost. In order to find the cost due to the weight we just have to multiply $2.50 by the number of pounds:
$2.50x
Since it will cost $8 more, then the total cost is $8 added to the cost due to the number of pounds:
In order to find the cost of shipping a 15-pound package,
we just replace x = 15 in the equation:
y = $2.50x + $8
y = $2.50 ยท 15 + $8
y = $37.5 + $8
y = $45.5