phillip bought 12 used cds and dvds.cds cost $2 each,and dvds cost $3 each.he spent $31,not including tax.how many dvds did phil

Question

Serga [27]

3 years ago

10

phillip bought 12 used cds and dvds.cds cost $2 each,and dvds cost $3 each.he spent $31,not including tax.how many dvds did phil

lip buy?

Mathematics

1 answer:

inessss [21] · Answer 1 · 2022-02-28T11:34:37+03:00

inessss [21]3 years ago

8 0

Let c and d be the number of cds and dvds respectively.

c+d=12

c=12-d

The we are told that:

2c+3d=31, using c found above in this equation gives you:

2(12-d)+3d=31

24-2d+3d=31

24+d=31

d=7

So Phillip bought 7 dvds.

check...

3*7+2(12-7)=31

21+2(5)=31

21+10=31

31=31