Could you show steps on how you solved? I've been having trouble.
Let x= the cost of the triple pack of CDs. A few key words we want to pay attention to are:
is means equals
less than means subtraction
of means multiplication.
So the double pack for $20 is (=) $4 less than (-4) + 3/4 the cost of (*) the triple pack (x)
Removing the words, we get 20 = -4 + (3/4)x or 20 = (3/4) x - 4
That should get you started. Solve for x.