Question

So if the length of one side of a square field is represented by the expression 3-7x .

Write an expression for the perimeter of the field expressed as a sum.

Answer 1

perimeter = 12 - 28x

Explanation:

The picture below is a square. It has four sides . All the sides are equal . Since one side of the square is given as 3 - 7x, the other side is also 3 - 7x.

The perimeter of a square is the sum of all sides . The sum of the square can be computed as

perimeter = L + L + L+ L

perimeter = 4L

length = 3 - 7x

Perimeter = 3 - 7x + 3 - 7x + 3 - 7x + 3 - 7x

perimeter = 3 + 3 + 3 + 3 -7x - 7x - 7x - 7x

perimeter = 12 - 28x

Answer 2

So plugging in what we are given
3-7x
| |
3-7x|___|3-7x
3-7x
To find the perimeter you add up all the sides
so
(3-7x) + (3-7x) + (3-7x) + (3-7x) = P
then we combine like terms
3 + 3 + 3 + 3 -7x -7x -7x -7x = P
9 + 9 -14x -14x = P
- 28x + 18 = P

Hope this helps :)