The answer would be 2/7, because 3 and 5 are the only factors of 15. 2/7 which is about 29 percent.
Well 5 is -10 km away from -5. We can further prove this by adding -5 + 10, giving us 5. Answer is 10!
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
1, 10, 25, 50, and so on...
