Math
posted by Nadia .
Suppose the central Park Coffee Shop sells a cup of expresso for 2.00 and a cup of cappuccino for 2.50. On Friday Destiny sold 30 more cups of cappuccino than expresso for a total of 178.50, worth of expresso and cappuccino. How many cups of each were sold?
I am learion to learning about weighted averages and we are suppose to make a chart and equation. I think my chart is right but i cant seem to make an equation that makes sense. Please please help me!!!!!!

C=E+30
2E+2.5C=178.5 
Im sorry but i do not see how to solve. I just figured out that it is 53 cappuccinos and 23 expressos, but i can not make an equation that shows how I got those two numbers.