Step-by-step explanation:
To find the perimeter of something, we add all of the measurements of the sides together.
A rectangle has 4 sides, this means we must double the algebraic hints given to us.
If we add them all up together it will look like this:
x-9+x-9+3x-4+3x-4=138
If we simplify it by collecting the like terms:
8x-26=138
We add 26 onto 138
8x=164
To find out what x equals, we divide by 8:
164÷8= 20.5
Answer:
x=20.5cm
x-9 is 11.5
3x-4 is 57.5
I know that you will not give 100 points but just wanted to help.
