Victorium bought 9 fiction books of the same kind during the Grand Opening Sale. Jaslyn bought 3 of the same fiction books. Jaslyn also bought 5 stickers at $2.50 each. Altogether, she spent $1.70 more than Victorium. What was the amount Jaslyn spent?
Amount that Jaslyn spent on 5 stickers
= 5 x 2.50
= $12.50

Let the cost of each fiction book be 1 u. 

Amount that Victorium spent = 9 u

Amount that Jaslyn spent =  3 u + 12.50

Jaslyn spent $1.70 more than Victorium.  If Victorium spent another $1.70, she would spend the same amount as Jaslyn.

9 u + 1.70 = 3 u + 12.50
9 u - 3 u = 12.50 - 1.70
6 u = 10.80

1 u = 10.80 ÷ 6 = 1.80

Cost of each fiction book
= 1 u
= $1.80

Amount that Jaslyn spent
= 3 x 1.80 + 12.50
= 5.40 + 12.50
= $17.90

Answer(s): $17.90