SOLUTION: I have a question concerning substitution and elimination. Goes like this: Maria drove from Owen Sound to Ottawa, a distance of 550 km. The trip took 7 h. Maria drove at 70 km/h

Algebra ->  Expressions-with-variables -> SOLUTION: I have a question concerning substitution and elimination. Goes like this: Maria drove from Owen Sound to Ottawa, a distance of 550 km. The trip took 7 h. Maria drove at 70 km/h      Log On


   



Question 105328: I have a question concerning substitution and elimination. Goes like this:
Maria drove from Owen Sound to Ottawa, a distance of 550 km. The trip took 7 h. Maria drove at 70 km/h for part of the trip and at 85 km/h for the remainder of the trip. How far did she drive at 70 km/h?
Can you please answer this detailed for me>?

Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
70T+85(7-T)=550
70T+595-85T=550
-15T=550-595
-15T=-45
T=-45/-15
T=3 HOURS DRIVEN @ 70KM/H
7-3=4 HOURS DRIVEN @ 85 KM/H
PROOF
70*3+85*4=550
210+340=550
550=550