You have $47 to spend at the music store. Each cassette tape costs $5 and each D costs $10. If #x# represents the number of tapes and # y # the number of CDs, what is the linear inequality that represents this situation?

1 Answer
Feb 2, 2017

Please see below.

Explanation:

As each cassette tape costs #$5# and each CD costs #$10#,

#x# number of tapes and #y# number of CDs will cost

#5xx x + 10 xx y=5x+10y#

i.e. one will have to pay #5x+10y# to purchase #x# number of tapes and #y# number of CDs.

But one cannot spend more than #$47# as that is the amount with me.

Hence we should have

#5x+10y<=47#

the linear inequality that represents this situation.

The solution will be given by
graph{5x+10y<=47 [-6.75, 13.25, -2.96, 7.04]}

and one can purchase #x# number of tapes and #y# number of CDs, where #x# and #y# are as per coordinates of a point in the shaded region.

But note that #x>=0# and #y>=0# as we cannot have negative number of tapes and negative number of CDs bur can choose no tapes or no CDs or both.

Hence, possible solutions are only integral values in #DeltaABC# below.
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