Question

The perimeter of the quadrilateral is 31x - 12 meters. Find the missing side length of the quadrilateral.

7x + 9

13x - 15

10 - 2x

Answer 1

Answer: The missing side length of the quadrilateral is 13x - 16.

Explanation:

We are given that the perimeter (P) of the quadrilateral is 31x - 12.

• P = 31x - 12

We are also given 3 of the 4 side lengths of the quadrilateral.

• 7x + 9
• 13x - 15
• 10 - 2x

We are asked to find the missing side length of the quadrilateral.

To find the missing side length we should:

• First understand that if we had all 4 side lengths that would equal the perimeter (31x - 12).
• Since we have three of the four side lengths of the quadrilateral, we can add them all up the subtract that amount from the perimeter to find the missing side length.

Step 1: Add the given sides:

7x + 9 + 13x - 15 + 10 - 2x

After combining like terms you get,

18x + 4

Step 2: Subtract -> Perimeter - total side lengths

(31x - 12) - (18x + 4)

distribute the negative:

31x - 12 - 18x - 4

Combine liker terms:

13x - 16

The missing side length of the quadrilateral is 13x - 16.