SOLUTION: A can travels for two hours at an average speed of 40 miles per hour. For how long must the can then travel at an average speed of 55 miles per hour to raise the overall average sp

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A can travels for two hours at an average speed of 40 miles per hour. For how long must the can then travel at an average speed of 55 miles per hour to raise the overall average sp      Log On


   

Question 129519: A can travels for two hours at an average speed of 40 miles per hour. For how long must the can then travel at an average speed of 55 miles per hour to raise the overall average speed to 45 miles per hour? What is the total time traveled?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
let x="time @ 55mph"

(2(40)+x(55))/(2+x)=45

multiplying by 2+x __ 80+55x=90+45x __ 10x=10