2 cassettes & 3CD's cost $175 while 4 cassettes & 1 CD cost $125.

(1) Given that 1 cassette cost $x & 1CD cost $y , write 2 equations in x & y to represent the information .

(2) calculate the cost of 1 cassette

Solution:

(1)

2x+3y=175

4x+y = 125

(2)

We solve the equations

x=20, y = 45

So the cost of 1 cassette is $20