1. The growth rate equation has a general form of:
y = A (r)^t
The function is growth when r≥1, and it is a decay when
r<1. Therefore:
y=200(0.5)^2t -->
Decay
y=1/2(2.5)^t/6 -->
Growth
y=(0.65)^t/4 -->
Decay
2. We rewrite the given equation (1/3)^d−5 = 81
Take the log of both sides:
(d – 5) log(1/3) = log 81
d – 5 = log 81 / log(1/3)
d – 5 = - 4
Multiply both sides by negative 1:
- d + 5 = 4
So the answer is D
Gavin needs $80 to buy a fish tank. He has saved $8 and plans to work as a babysitter to earn $9 per hour. Which inequality shows the minimum number of hours, n, that Gavin should work as a babysitter to earn enough to buy the fish tank? 8 + 9n ≥ 80, so n ≥ 8 8 + 9n ≤ 80, so n ≤ 8 9n ≥ 80 + 8, so n ≥ 9.8 9n ≤ 80 + 8, so n ≤ 9.8
Answer:
2t + 16
Step-by-step explanation:
1. 0 seconds and 16 feet.
2. 1 second and 18 feet.
3. 2 seconds and 20 feet.
4. 3 seconds and 22 feet.
5. 6 seconds and 28 feet.
Therefore, the answer is 2t + 16.
