Answer:
Step-by-step explanation:
Given that a large mixing tank initially holds 400 gallons of water in which 70 pounds of salt have been dissolved. Pure water is pumped into the tank at a rate of 4 gal/min, and when the solution is well stirred, it is then pumped out at the same rate.
Let Q(t) be the quantity of salt at time t.
Q(0) = 70 pounds
Inflow of water = outflow = 4 gal/min
So resulting volume of tank at time t = 400 gallons
Rate of change of salt = inflow - outflow
= 0 - 
i.e. 
This is a variable separable equation

Use when t =0 Q = 70
A =70
So A(t) = Q(t) =
and
A(0) = Q(0) = 70 lbs.
Answer:
D
Step-by-step explanation:
-10° C is the lowest temperature and 7°C is the highest temperature.
Answer:
x = 5.5 to the nearest tenth.
Step-by-step explanation:
Here we have a right triangle with one angle (65 degrees) given. Side x is the "side adjacent to the angle" and is to be found. The hypotenuse is 13.
The cosine function makes use of these three knowns: the angle, the hypotenuse and the adjacent side. Thus:
cos 65 degrees = adj / hyp = x / 13, or
x = 13 cos 65
Evaluating this on a calculator, we get x = 5.49, or x = 5.5 to the nearest tenth.
Answer:
80
Step-by-step explanation:
Angle VSU = 100. Angles TSU is a linear pair with angle VSU so adding them together equals 180. 180-100=80.