4=x+13 -17=3+x
x+4=-9
x-3=-7
22+x=7
-8x=-64
-96=4x
11=22x
7x=-7/2
x/7=12
35=x/5
-39=x/3
m/4=-17/2
2/3x=18
3/4x=9
5/8y=-1
3/5m=-15
1/5x=2/7
36=4/9x

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.