Answer:
Step-by-step explanation:
smplifying
7x + 11 = 25
Reorder the terms:
11 + 7x = 25
Solving
11 + 7x = 25
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-11' to each side of the equation.
11 + -11 + 7x = 25 + -11
Combine like terms: 11 + -11 = 0
0 + 7x = 25 + -11
7x = 25 + -11
Combine like terms: 25 + -11 = 14
7x = 14
Divide each side by '7'.
x = 2
Simplifying
x = 2
Answer:
A(t) = 300 -260e^(-t/50)
Step-by-step explanation:
The rate of change of A(t) is ...
A'(t) = 6 -6/300·A(t)
Rewriting, we have ...
A'(t) +(1/50)A(t) = 6
This has solution ...
A(t) = p + qe^-(t/50)
We need to find the values of p and q. Using the differential equation, we ahve ...
A'(t) = -q/50e^-(t/50) = 6 - (p +qe^-(t/50))/50
0 = 6 -p/50
p = 300
From the initial condition, ...
A(0) = 300 +q = 40
q = -260
So, the complete solution is ...
A(t) = 300 -260e^(-t/50)
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The salt in the tank increases in exponentially decaying fashion from 40 grams to 300 grams with a time constant of 50 minutes.
This abosoulutly makes no snse
For this case we have the following solution.
x = gallons of water to be added
For the 10% solution we have:
0.1 * 8 = 0.8
Then, for 5% we have:
(0.8 / x + 8) = 0.05
Rewriting:
(0.8 / x + 8) = (5/100)
Answer:
An equation can be used to find x, the humber of gallons of water he should add is:
(0.8 / x + 8) = (5/100)
Each pound costs 2.40,
to check this 2.40 * 5 = 12
so 2.40 * 7 = 16.80
Answer: 16.80
