Question

As Marta built a square fence around her garden, she wondered how much she would have to pay if she increased the length of each side of the fence by the same number of meters. Each meter of fence cost 3 dollars. Which of the following functions best describes the additional amount of money Marta will have to spend, in dollars, if she increases each side of the fence by m meters?

A. f(m) = 1.5m

B. f(m) = 3m

C. f(m) = 6m

D. f(m) = 12m

Answer 1

meters is given I say about C = 12m so answer is D

Answer 2

The answe is D) f(m)= 12 * m

Explanation:

If Marta is building a square fence, the function that describes the cost is:

Being:

• m=meters

• Cost= 3 $/m

• 4 equal sides
• The function for the perimeter of a square is four times it´s side.
• The function for the cost is the perimeter multiplied by the unit cost of the meter.

f(m)= 4 * m *3 $/m

f(m)= 12 * m

So the correct answer is D.