Posted by john on Sunday, September 16, 2012 at 4:11pm.
to travel 132 miles it take sue riding a moped 2 hours less time then it takes doreen to travel 56 miles riding a bike. sue travels 15 miles per hour faster then doreen find the time and rates
- college algebra - Henry, Monday, September 17, 2012 at 5:24pm
Doreen's speed = X mi/h
Doreen's time = Y hrs(d = 56mi).
Eq1: X*Y = 56.
Y = 56/X
Sue's speed = (X+15) mi/h.
Sue's time = (Y-4) hrs(d = 132mi).
Eq2: (X+15)(Y-4) = 132.
In Eq2, substitute 56/X for Y:
(X+15)(56/X-4) = 132
56-4x+840/x-60 = 132
-4x+840/x-4 = 132
Multiply both sides by X:
-4x^2+840-4x = 132x
-4x^2-136x+840 = 0
Divide both sides by -4:
x^2+34x-210 = 0.
Use Quad. formula.
X = 5.34 mi/h = Doreen's speed.
X+15 = 5.34+15 = 20.34 mi/h=Sue's speed.
Y = 56/X = 56/5.34 = 10.5 h. = Doreen's
Y-4 = 10.5-4 = 6.5 hrs = Sue's hrs.
Answer this Question
More Related Questions
- Math - To travel 175 miles, it takes Sue, riding a moped, 4 hours less time than...
- Algebra 2 - It takes You, riding a motorcycle, 2 hours less time to travel 60 ...
- algebra - A train can travel 280 miles in the same time that it takes a car to ...
- college algebra - Solve the problem. A man rode a bicycle for 12 miles and then ...
- Pre-Algebra - Courtnytravels south on her bicycle riding 8 miles per hour. One ...
- algebra - INTRODUCTION TO RATIONAL EXPRESSIONS Distance and Time A car is ...
- Algebra 1 - You are 36 miles from a friend. You both start riding your bicycles ...
- intermediate algebra - You can travel 40 miles on a motorcycle in the same time ...
- Math - Two cars start from the same place and travel in the same direction. If ...
- Math - You ride your bike at an average speed of 8 miles per hour.how many miles...