A family has two cars. During one particular week, the first car consumed \( 15 \) gallons of gas and the second consumed \( 30 \) gallons of gas. The two cars drove a combined total of \( 1050 \) miles, and the sum of their fuel efficiencies was \( 45 \) miles per gallon. What were the fuel efficiencies of each of the cars that week? Note that the ALEKS graphing calculator can be used to make computations easier.
First car: 20 miles per gallon
Second car: 25 miles per gallon