Austin spent an equal amount of money on 5 DVDs and 7 CDs. Each DVD cost 30 cents more than each CD. How much did Austin spend altogether?

Answer 1

Austin spent $9.00 (nine dollars) altogether.
Work:
CD=x
DVD=x+30
7x=5(x+30)=5x+150
2x=150
x=75
7x+5x=12x=900 Ans.

Answer 2

correct until the last line.
7x+5(x+30) =
7*75 + 5*105 = 525+525 = $10.50