math
posted by rufus on .
Two cassettes and three cd's cost $175 while four cassettes and one cd cost $125.
1)Given that one cassette cost $x and one cd cost $y,write two equations in x and y to represent this information.
2)Calculate the cost of one cassette.

1. just translate the English into Math
"Two cassettes and three cd's cost $175" > 2x + 3y = 175
"four cassettes and one cd cost $125" > 4x + y = 125
2. double the first equation
4x + 6y = 350 then subtract the second
4x + y = 125

5y = 225
y = 45
back in the second
4x + 45 = 125
4x = 80
x = 20
(expensive cassettes and CDs) 
2x+3y

5