1. Suppose you get a job selling T-shirts at a concert. You get $2 for each T-shirt you sell, but it costs you $5 to get into the concert. How many T-shirts will you have to sell in order to come home with $25?

 

Let x = the number of T-shirts you sell. If you get $2 for each T-shirt you will make $2x, but if you have to pay $5 to get into the concert, the amount of money you make will be given by the formula 2x - 5. If the amount of money you need to bring home is $25, we get the equation

 

2x - 5 = 25

 

Add 5 to both sides

 

2x - 5 = 25

+ 5 +5

2x = 30

 

Divide both sides by 2

 

x = 30/2

or

x = 15 T-shirts.