Answer:
dy/dt = 7y / (t − 1000)
Step-by-step explanation:
Change in mass of salt = mass of salt going in − mass of salt going out
dy/dt = 0 − (C kg/L × 7 L/min)
where C is the concentration of salt in the tank.
The concentration is mass divided by volume:
C = y / V
The volume in the tank as a function of time is:
V = 1000 + 6t − 7t
V = 1000 − t
Therefore:
C = y / (1000 − t)
Substituting:
dy/dt = -7y / (1000 − t)
dy/dt = 7y / (t − 1000)
If we wanted, we could separate the variables and integrate. But the problem only asks that we find the differential equation, so here's the answer.
F(3)= 2(3)^2-5(3)+9
=2(9)-15+9
=18-15+9
=3+9
=12
f(3)=12 or B
Answer:
x = 8/5
Step-by-step explanation:
0 = - 2 x 2+5 x - 4
Answer:42
Step-by-step explanation:
Answer:
x = 16
Step-by-step explanation:
The angle vertically opposite (4x - 17) is also (4x - 17) , then
4x - 17 and 8x + 5 are same- side interior angles and sum to 180° , that is
4x - 17 + 8x + 5 = 180
12x - 12 = 180 ( add 12 to both sides )
12x = 192 ( divide both sides by 12 )
x = 16
