Answer:
y= 7^-t
Step-by-step explanation:
Equation for exponential decay:
An equation represents exponential decay if a term between 0 and 1 is elevated to the independent variable.
In this question:
First option 4 is elevated, so not exponential decay.
Second option:

, thus, the second option represents exponential decay.
Answer:
The length of the park is 175 feet
Step-by-step explanation:
Let us solve the question
∵ The perimeter of a rectangular park is 500 feet
∵ The formula of the perimeter of the rectangle is P = 2(L + W)
∵ L is the length and W is the width
→ Equate the rule of the perimeter by 500
∴ 2(L + W) = 500
→ Divide both sides by 2
∴ L + W = 250 ⇒ (1)
∵ The length of the park is 100 feet longer than the width
→ That means L is W plus 100
∴ L = W + 100 ⇒ (2)
→ Substitute L in (1) by (2)
∵ W + 100 + W = 250
→ Add the like terms
∵ (W + W) + 100 = 250
∴ 2W + 100 = 250
→ Subtract 100 from both sides
∵ 2W + 100 - 100 = 250 - 100
∴ 2W = 150
→ Divide both sides by 2
∴ W = 75
→ Substitute the value of W in (2) to find L
∵ L = 75 + 100 = 175
∴ The length of the park is 175 feet
Use substitution
x -4x - 7 = 2
-3x = 9, x = -3
Y = -4(-3) - 7
Y = 12 - 7, y = 5
Solution: x = -3, y = 5
88 divided by 1/4 can be placed like this: 88/1 divided by 1/4, which should lead to an answer of 22/1 or 22. Then you add 20, so 22 plus 20 would equal 42. 42 is the correct answer.