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)
Theres an app called photomath thats useful for these kinds of problems
Answer:
Yes.
Step-by-step explanation:
Both yards do cost the same.
$15.00 divided by 2 is equal to 7.5.
$37.50 divided by 5 is equal to 7.5.
Therefore, both yards cost the same.
4x-4>20
Step 1: Add four to both sides
4x-4+4>20+4
4x>24
Step 2: Divide both sides by 4
4x divided by 4 and 24 divided by 4
Answer: x>6
Kahal accidentally subtracted instead of adding. He made a mistake in step 2.
Circumference is 40 in and area is 150 in²
Step-by-step explanation:
- Step 1: Find the circumference of the circle when radius = 7 in
Circumference = 2πr = 2 × 22/7 × 7 = 44 in ≈ 40 in
- Step 2: Find the area of the circle.
Area = πr² = 22/7 × 7² = 154 in² ≈ 150 in²
