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)

7 0

3 years ago

A rectangle has a length that is 7 inches less that twice it's width. The area of the rectangle is 72 square inches. Write an eq

Nitella [24]

Answer: $2x^2-7x=72$ , where x= width of the rectangle ( in inches).

Step-by-step explanation:

Let x= width of the rectangle ( in inches).

Then its length = 2x-7 ( in inches).

Area of rectangle = Length × width

= (2x-7) × (x)

= 2x × x -7 ×x

= 2x²-7x

The area of the rectangle is 72 square inches.

$\Rightarrow\ 2x^2-7x=72$

Hence, the equation that represents the given situation :

$2x^2-7x=72$

7 0

3 years ago

How much is 608 divided 19 in area model

AVprozaik [17]

Answer:

608 ÷ 19 = 32

Step-by-step explanation:

608 ÷ 19 = 32

Hope this helps! :)

5 0

3 years ago