Which phrase could be represented by this expression?       k/5 + 8 or  k over 5 + 8 eight more than a fifth of a number five times a number plus eight eight more than five times a number one-fifth of the sum of a number and eight

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.