SOLUTION: Gemma recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 10 miles per hour faster than on her way home. If gemma spent a

Algebra.Com
Question 915232: Gemma recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 10 miles per hour faster than on her way home. If gemma spent a total of 1 hour bicycling,find The two rates?
Answer by mananth(16946)   (Show Source): You can put this solution on YOUR website!
on her way home speed x
onn her way there speed x + 10

Distance = same 12 miles 1
original time – time with increased speed = 1 hour
t=d/t
12 / x - 12 / ( x + 10 ) = 1
LCD= x ( x + 10 )
multiply by LCD
12 ( x + 10 ) - 12 x = 1 x ( x + 10 )
12 x + 120 - 12 x = 1 X^2 + 10 x
120 = 1 X^2 + 10 x
1 X^2 + 10 x - -120 = 0
Find roots of the quadratic equation
a= 1 b= 10 c= -120

x1= ( -10 + sqrt( 100 - 480 )) / 2
x1=( -10 + 24.08 )/ 2
x1= 7.04

x2= ( -7 - sqrt( 49 - 20 ) / 2
x2=( -10 - 24.08 )/ 2
x2= -17.04
17.04 m/h, and 7.14 m/h

RELATED QUESTIONS

Caitlin recently rode her bicycle to visit her friend who lives 12 miles away. On her way (answered by ewatrrr)
Carmen recently rode her bicycle to visit her friend who lives 12 miles away. On her way... (answered by ankor@dixie-net.com)
How do I do this word problem? Carmen recently rides her bicycle to visit her friend who (answered by richwmiller)
Jen recently rode her bike to visit her friend who lives 12 miles away. On her way there, (answered by josmiceli)
Mary left home at 12 noon and drove to visit her mom who lives 20 miles away. After she... (answered by khwang,kiru_khandelwal)
Mary left home at 12 noon and drove to visit her mom who lives 20 miles away. After she... (answered by josmiceli)
Allison drove to visit her aunt who lives 354 miles away. It took her 6 hours to get... (answered by josmiceli)
Allison drove to visit her aunt who lives 174 miles away. It took her 3 hours to get... (answered by solver91311)
Jamie recently drove to visit her parents who live 420 miles away. On her way there her... (answered by t0hierry,MathTherapy)