Question if u ask a question will it take your points away

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8

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.

Percent increase and decrease. original number: 45 new number: 18