Answer: 100 = 10d + 5
Explanation:
Dolls are sold for $10 each so when checking the total amount made from the sale of d dolls you will multiply d by the price of each doll:
= 10 * d
= 10d
There is a $5 charge for shipping but this is one time so it is added to the total price of d dolls:
= 10d + 5
The total made was $100 so the equation above should equal $100:
100 = 10d + 5