5215875 round millions

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

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.