can yall help me solve this (3b^3 + 2b^2 + 4b +5) +(9b+9) example this is 3b to the power of 3 just saying (if that even made any sense) BUT PLZ HEL

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.