Steve bought a total of 8 tapes and CD's. Each tape cost $12 and each CD cost $18. How many tapes and how many CD's did he buy if he spent a total of $126?
t=tapes
c=CD's
t+c=8
12t+18c=126
multiply {c+t=8} by -12 and set up your system of equations
-12t-12c=-96
6c=30
c=5
t=3
check:
5+3=8 yes :)
12(3)+18(5)=126 also yes :)
therefore c=5, t=3
