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.
<span>g(x) = x^2 + 4x + 3
y-intercept: let x=0. Then y=3. y-intercept is (0,3).
roots: set g(x) = 0 and solve for x. x=-1 and x=-3.
-4
axis of symmetry: find x = -b / (2a), which here is x = ----- = -2
2</span>
Answer:
40
Step-by-step explanation:
6% of number = 6/100 × x = 6x/100 = 3x/50
Sum of the number and 6% of itself = 42.4
x + (3x/50) = 42.4
(50x+3x)/50 = 42.4
53x = 42.4 × 50
53x = 2120
x = 2120/53
x = 40
Answer:
4 units
Step-by-step explanation:
Perimeter formula is P = 2L + 2W. Here P = 34 units = 2L + 2(6.5 units).
Reducing this, 17 = L + 13. Then L = 4 units.
Answer:
3520 yards
Step-by-step explanation:
1 mile = 1760 yards
2 miles = 2(1760)=3520 yards