#7. Three friends each ordered two slices of pizza and a drink at the mall. If the drinks cost $1.70, and the total of their order was $21, how much did one slice of pizza cost?

Step-by-step explanation:

Let each slice of pizza = x

One person orders 2 slices of pizza which = 2x

3 people order 3 * 2x = 6x

Each person orders a drink at 1.70 per drink

3 people order a drink = 3 * 1.70 = 5.10

The total order is 21 dollars. So the left side of the equation will be

6x + 5.10 = 21                    Subtract 5.10 from 21

     - 5.10     5.10

6x   =          15.90              Divide both sides by 6

6x/6 =         15.90/6

x     =            2.65

Each slice of pizza costs $2.65