Answer:
D = L/k
Step-by-step explanation:
Since A represents the amount of litter present in grams per square meter as a function of time in years, the net rate of litter present is
dA/dt = in flow - out flow
Since litter falls at a constant rate of L grams per square meter per year, in flow = L
Since litter decays at a constant proportional rate of k per year, the total amount of litter decay per square meter per year is A × k = Ak = out flow
So,
dA/dt = in flow - out flow
dA/dt = L - Ak
Separating the variables, we have
dA/(L - Ak) = dt
Integrating, we have
∫-kdA/-k(L - Ak) = ∫dt
1/k∫-kdA/(L - Ak) = ∫dt
1/k㏑(L - Ak) = t + C
㏑(L - Ak) = kt + kC
㏑(L - Ak) = kt + C' (C' = kC)
taking exponents of both sides, we have

When t = 0, A(0) = 0 (since the forest floor is initially clear)


So, D = R - A =

when t = 0(at initial time), the initial value of D =

Answer:
The price of the watch is 280$
Step-by-step explanation:
We know that the original price is 400 dollers, and its on sale for 30%.
So we do 30% of 400 = 120$
finally we do, 400$ - 120$ = 280$
so the final price of the watch is 280$
hope this helps
Answer:
∠F ≈ 53°
General Formulas and Concepts:
<u>Trigonometry</u>
- sin∅ = opposite over hypotenuse
- sin inverse evaluates "backward" to find the measure angle
Step-by-step explanation:
<u>Step 1: Define</u>
Looking at ∠F
opposite leg of ∠F = ED = 8
hypotenuse = FE = 10
<u>Step 2: Find m∠F</u>
- Substitute: sin∠F = 8/10
- Simplify: sin∠F = 4/5
- Take sin inverse: ∠F = sin⁻¹(4/5)
- Evaluate: ∠F = 53.1301°
- Round: ∠F ≈ 53°
You have to factor by grouping.
(4a - 5) (a + 4)