SOLUTION: Need assistance with this, i cant figure it out. It's driving me mad. Thank you. Lena is choosing between two exercise routines. In routine #1, she burns 25 calories walking.

Algebra ->  Inequalities -> SOLUTION: Need assistance with this, i cant figure it out. It's driving me mad. Thank you. Lena is choosing between two exercise routines. In routine #1, she burns 25 calories walking.      Log On


   

Question 529309: Need assistance with this, i cant figure it out. It's driving me mad. Thank you.
Lena is choosing between two exercise routines.
In routine #1, she burns 25 calories walking. She then runs at a rate that burns 18 calories per minute.
In routine #2, she burns 49 calories walking. She then runs at a rate that burns 14 calories per 
minute.
For what amount of time spent running will routine #1 burn fewer calories than routine#2? Use t for the number of minutes spent running, and solve your inequality for t.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let t = minutes spent running
given:
Routine #1
Calories burnt = +25+%2B+18t+
Routine #2
Calories burnt = +49+%2B+14t+
------------------------
Let calories burnt = C
The question is:
for what values of t is
+49+%2B+14t+%3E+25+%2B+18t+
Subtract +14t+ from both sides
+49+%3E+25+%2B+4t+
Subtract +25 from both sides
+24+%3E+4t+
+6+%3E+t+
or, what is the same,
+t+%3C+6+
So, for all values of t+%3C+6+ minutes spent running,
The calories burnt using routine #1 are less than
the calories burnt using #2
Here's a plot of routine #1 and #2:
+graph%28+400%2C+400%2C+-1%2C+7%2C+-5%2C+150%2C+18x+%2B+25%2C+14x+%2B+49+%29+
The bottom line is routine #1. You can see that when +t+=+0+
+C+=+25+ as it should, and they meet at t=6