Shopping at savers mart, Lisa buys her children four shirts and three pairs of pants for $85.50. She returns the next day and buys three shirts and five pairs of pants for $115.00. What is the price of each shirt and each pair of pants?

So you have to make two equations. Let's say x stands for shirts and y stands for pants. 4x+3y=85.50. The second equation would be, 5y=115-3x. Since you need one of them to have x = or y=, you need to change it to that form. y=. Then you do substitution and solve which leaves you with:

Shirts are $7.50

Pants are $18.50