Answer:
dA/dt = k1(M-A) - k2(A)
Step-by-step explanation:
If M denote the total amount of the subject and A is the amount memorized, the amount that is left to be memorized is (M-A)
Then, we can write the sentence "the rate at which a subject is memorized is assumed to be proportional to the amount that is left to be memorized" as:
Rate Memorized = k1(M-A)
Where k1 is the constant of proportionality for the rate at which material is memorized.
At the same way, we can write the sentence: "the rate at which material is forgotten is proportional to the amount memorized" as:
Rate forgotten = k2(A)
Where k2 is the constant of proportionality for the rate at which material is forgotten.
Finally, the differential equation for the amount A(t) is equal to:
dA/dt = Rate Memorized - Rate Forgotten
dA/dt = k1(M-A) - k2(A)
Answer:
20
Step-by-step explanation:
<u>15</u> = <u>75</u>
x 100 (then cross multiply below)
---------------------------
<u>1,500</u> = <u>75x </u>
75 75
20 = x
Answer:
9 ft, 28 ft, 26 ft
Step-by-step explanation:
The perimeter is the sum of side lengths, so ...
P = a + b + c
63 = n +(4n -8) +(2n +8) . . . . fill in the given side lengths
63 = 7n . . . . . . simplify
9 = n . . . . . . . . divide by 7
4n -8 = 36 -8 = 28 . . . . second side length
2n +8 = 18 +8 = 26 . . . . third side length
The side lengths are 9 ft, 28 ft, 26 ft..
<span>for y varies directly with x, you should have
y=kx
where k is constant of variation.ok</span>
15% of 60 = 9.
15/100 • 60 = 9.
I hope that helped! c: