Which equation can be used to find the answer?

A fence with four sections has a perimeter of 43 ft. Three of the sections have lengths of 8 ft, 12 ft, and 11 ft. What is the length of the fourth section?

x - 8 + 12 + 11 = 43

x = 43 + 8 + 12 + 11

x - 43 = 8 + 12 - 11

x + 8 + 12 + 11 = 43

x + 8 + 12 + 11 = 43

Step-by-step explanation:

this one is the one to find x

basically subtract all those numbers from 43 to get 12 ft.

-You know that the fence is 40ft, so we can infer that the perimeter of the garden is also 40ft.

-The formula for perimeter of a rectangle is 2 (length) + 2 (width) = P

- Since P is given, we'll rewrite this

as: 2 (length) + 2 (width) = 40ft

The length of your garden is 4 times as long as your width. But you don't have a value for your width. This is where you may need to substitute this missing value with x.

Since we know our width is now x, we can rewrite the perimeter formula

as: 2 (length) + 2 (x) = 40ft

Now we still need our lengths.

If the length is 4 times as much as the width, then we can write it as being 4 times x.

You're left with the equation

2 (4x) + 2 (x) = 40ft

which becomes 8x+2x=40ft

Solve for x and plug that back into the original question.

Don't forget to show your units.