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
28/36 will be your answer which can be simplified into 14/18 which can be simplified again to 7/9 and that's your final answer
Answer: 5000000000
Step-by-step explanation: i just know
3 ways because 12 divided by 4 is 3.
