Which rules define the function whose graph is shown?   on  x < −2   on  −2 ≤ x < 0   on  0 ≤ x < 2   on  2 ≤ x

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.