Please help me?! All you have to do is find the missing side

see explanation

Step-by-step explanation:

To find the missing side, subtract the sum of the 2 given sides from the perimeter.

(11)

6x + 6y - (2x + y + x + 2y)

= 6x + 6y - (3x + 3y)

= 6x + 6y - 3x - 3y ← collect like terms

= 3x + 3y ← missing side

(12)

11x + 2y - (2x + 3y + 6x - 5y)

= 11x + 2y - (8x - 2y)

= 11x + 2y - 8x + 2y ← collect like terms

= 3x + 4y ← missing side

the answer is 15% decrease

step-by-step explanation:

i think you should think about the question and not look online.