SOLUTION: You bike 50 miles from home. On your way back, your average speed increases by 3 miles per hour. A) Write an equation that gives the total biking time t (in hours) as a function

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: You bike 50 miles from home. On your way back, your average speed increases by 3 miles per hour. A) Write an equation that gives the total biking time t (in hours) as a function       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 957091: You bike 50 miles from home. On your way back, your average speed increases by 3 miles per hour.
A) Write an equation that gives the total biking time t (in hours) as a function of your average speed r (in miles per hour) when you are biking away from home. (Simplify)
B) Find the total biking time if you bike away from home at an average speed of 15 miles per hour. Round your answer to the nearest tenth.
C) How much longer is your total biking time if you bike away from your home at an average speed of 12 miles per hour?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Biking from home, ave. speed = +r+
Biking back home, ave. speed = +r+%2B+3+
(a)
+50+=+r%2At%5B1%5D+
+t%5B1%5D+=+50%2Fr+
-----------------
+50+=+%28+r+%2B+3+%29%2At%5B2%5D+
+t%5B2%5D+=+50%2F%28+r%2B3+%29+
+t%5B1%5D+%2B+t%5B2%5D+=+50%2Fr+%2B+50%2F%28+r%2B3+%29+
---------------
(b)
+t%5B1%5D+=+50%2F15+
-------------------
+t%5B2%5D+=+50%2F%28+15+%2B+3+%29%0D%0A%7B%7B%7B+t%5B2%5D+=+50%2F18+
-------------------
+t%5B1%5D+%2B+t%5B2%5D+=+50%2F15+%2B+50%2F18+
+t%5B1%5D+%2B+t%5B2%5D+=+%2850%2F3%29%2A%28+1%2F5+%2B+1%2F6+%29+
+t%5B1%5D+%2B+t%5B2%5D+=+%28+50%2F3%29%2A%28+6%2F30+%2B+5%2F30+%29+
+t%5B1%5D+%2B+t%5B2%5D+=+%28+50%2F3+%29%2A%28+11%2F30%29+
+t%5B1%5D+%2B+t%5B2%5D+=+%28+5%2F3+%29%2A%28+11%2F3+%29+
+t%5B1%5D+%2B+t%5B2%5D+=+55%2F9+
+t%5B1%5D+%2B+t%5B2%5D+=+6.1+ hrs
---------------
(c)
+t%5B1%5D+%2B+t%5B2%5D+=+50%2F12+%2B+50%2F15+
+t%5B1%5D+%2B+t%5B2%5D+=+25%2F6+%2B+20%2F6+
+t%5B1%5D+%2B+t%5B2%5D+=+45%2F6+
+t%5B1%5D+%2B+t%5B2%5D+=+15%2F2+
+t%5B1%5D+%2B+t%5B2%5D+=+7.5+
+7.5+-+6.1+=+1.4+ hrs longer
--------------
Hope I got these