SOLUTION: At top speed, my car could travel 175 miles in a given amount of time. After upgrading the engine to my car its top speed by 20 mph and it could travel 210 miles in the same amount

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: At top speed, my car could travel 175 miles in a given amount of time. After upgrading the engine to my car its top speed by 20 mph and it could travel 210 miles in the same amount      Log On


   

Question 101581This question is from textbook Beginning and intermedicate algebra
: At top speed, my car could travel 175 miles in a given amount of time. After upgrading the engine to my car its top speed by 20 mph and it could travel 210 miles in the same amount of time. What was the top speed of my car pre-upgrade?
My teacher wrote this problem himself and I couldnt find an example of this problem in my book. Therefore, I dont know where to start. Please help me so that I can do this problem in the future. Thank you!! This question is from textbook Beginning and intermedicate algebra

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
t=d/r ... time is the same, distance and rate change

t=175/r ... t=210/(r+20) ... 175%2Fr=210%2F%28r%2B20%29 ... 175(r+20)=210r

175r+3500=210r ... 3500=35r ... 100=r