Answer:
Step-by-step explanation:
Amount of brine = 100 gal
amount of salt = 80 lb
rate of water running = 4 gal / min
Let A be the amount of salt in lb in the tank at any time t.
(a) dA/dt = rate of salt in - rate of salt out
Rate of salt in = 0
rate of salt out = A x 4 / 100 = A / 25 lb/min
So, dA/dt = 0 - A/25 = - A/25 lb/min



When t = 0, A = 80 lb
So,

(b) Now, A = 40 lb
So,


take log on both the sides

t = 17.3 minutes
Just work the problem in reverse.
1:14pm - 24 minutes would be 12:50pm.
12:50pm - 15 minutes would be 12:35pm.
Jennifer left her house at 12:35pm.
X/3-10=12
x/3=-2
x=-6
p/5+10=14
p/5=4
p=20
Answer:
Step-by-step explanation:
3a^4 -2a^2 + 5 - 10 -(2a^4 +4a^2 + 5a -2)
as given.. i'm wondering if the 5 in the first group is really 5a.. hmmm
I'm guessing that it is... soooo distribute the minus sign
= 3a^4 - 2a^2 +5a -10 -2a^4 -4a^2 -5a +2
= a^4 -6a^2 -8 :) voila that's your answer