An expression is just like an equation but without the equal sign.
Answer:
XZ
Step-by-step explanation:
X and Z are points so that makes 2 endpoints, and a line segment
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