SOLUTION: Need help on how to solve these problems. Please include steps on how to solve. Thank you. A bathtub is being drained. Since it is an ordinary tub, it can be modeled by the func

Algebra ->  Linear-equations -> SOLUTION: Need help on how to solve these problems. Please include steps on how to solve. Thank you. A bathtub is being drained. Since it is an ordinary tub, it can be modeled by the func      Log On


   

Question 977470: Need help on how to solve these problems. Please include steps on how to solve. Thank you.
A bathtub is being drained. Since it is an ordinary tub, it can be modeled by the function
V(t) = -15t + 45 where V(t) is the volume of the tub in gallons and t is the time that has passed in minutes. V(T) = -20T + 50 where v(T) is the volume of the tub in gallons and T is the time that has passed. Which tub will drain faster?
Based on the function V(t) = -15t + 45, when will the tub be half full?

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
In other words, when does V%28t%29=0?
V%5B1%5D=-15t%2B45=0
15t=45
t%5B1%5D=3min
.
.
V%5B2%5D=-20t%2B50=0
20t=50
t%5B2%5D=5%2F2min
.
.
The second tub drains faster.
.
.
The first tub is half full when the volume is half of the volume at t=0.
V%5B0%5D%2F2=%28-15%280%29%2B45%29%2F2=45%2F2
-15t%2B45=45%2F2
-15t=-45%2F2
t=3%2F2min