SOLUTION: A motorist covers a distance of 210km. If his average velocity was 10km/h more, he would have completed the distance in half an hour less.
Calculate his average speed.
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-> SOLUTION: A motorist covers a distance of 210km. If his average velocity was 10km/h more, he would have completed the distance in half an hour less.
Calculate his average speed.
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Question 894909: A motorist covers a distance of 210km. If his average velocity was 10km/h more, he would have completed the distance in half an hour less.
Calculate his average speed.
Thanks. Answer by richwmiller(17219) (Show Source):
You can put this solution on YOUR website! r*t=d
r*t=210
(r+10)*(t-1/2)=210
r*t=(r+10)*(t-1/2)
rt+10t-r/2-5=210
10t-r/2-5=0
10*210/r-r/2-5=0
2100/r-r/2-5=0
4200-r^2-10r=0
r^2+10r-4200=0
(r-60)*(r+70)=0
r=60 t=3.5
check
60*3.5=210
70*3=210
ok
