Answer:
The work shown here is correct.
It simplifies to 17x + 36y + 5.
Explanation:
In this situation, there are four different items being purchased. This means their will be a sum of 4 terms. Each term will be the number of the item times its cost. When added together, the four terms will represent the total cost.
7 pens at $x is 7x
5 pens at $(2x+3) is 5(2x+3)
y pens at $6 is 6y
(3y-1) pens at $10 each is 10(3y-1)
All together the cost expression is 7x + 5(2x+3) + 6y + 10(3y -1).
Simplify by applying the distributive property and combine like terms.
7x + 10x + 15 + 6y + 30y - 10
17x + 36y + 5