Question 1039970
Let n be the slower speed. Then:
100/n+120/(n+10)=4
100n+1000+120n=4nē+40n
4nē-180n-1000=0
nē-45n-250=0
(n+5)(n-50)=0
n=50 kmh for the slower speed, 60 kmh for the faster speed!!!!!!!!!!!!