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:
See below in bold.
Step-by-step explanation:
The cost of what he wants to buy = 4.25 + 0.89 + 10.99
= $16.13
a) He does have enough to buy everything.
b) He has 20 - 16.13 = $3.87 left over.
Answer:
its 20
Step-by-step explanation:
PEMDAS.
Answer:
x=5+b/2
Step-by-step explanation:
move all terms that dont contain x to the right, and solve
