SOLUTION: A trucker drove 180 miles to make a delivery and returned home on the same route. Because of foggy conditions, his average speed on the return trip was 10 mph less than his average

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: A trucker drove 180 miles to make a delivery and returned home on the same route. Because of foggy conditions, his average speed on the return trip was 10 mph less than his average      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 869689: A trucker drove 180 miles to make a delivery and returned home on the same route. Because of foggy conditions, his average speed on the return trip was 10 mph less than his average speed going. If the return trip took 3 hours longer, how fast did he drive in each direction?
going___________mph
returning___________mph
Help me out this is due tomorrow please!
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let forward direction speed =x mph
return speed = x-10
180/x = 180/(x-10)-3

180/(x-10)-180/x =3
multiply by x(x-10)
180x-180(x-10)=3x(x-10)
180x-180x+1800=3x^2-30x
3x^2-30x-1800=0
/3
x^2-10x-600=0
x^2-30x+20x-600=0
x(x-30)+20(x-30)=0
(x-30)(x+20)=0
x=30 taking positive value
going = 30 mph
returning = 20 mph