Answer:
Equation:
or 
Solution:
Step-by-step explanation:
The formula that is used to calculate the perimeter of a square is:

Where "s" is the side lenght the square.
Knowing that Xin used 20 yards of fencing to build the walls of a square chicken coop (in which the lenght in yards of each wall is represented with "x"), you can identify that:

Then, you can susbtitute values into the formula
:
Finally, you must solve for "x" in order to find its value.
This is:

Answer: 40 %
Step-by-step explanation:
Let the amount of one card = x
Hence, the value of 20 cards ( Principal amount ) = 20x
And, the value of 22 cards ( Total amount after 3 month ) = 22x
⇒ Total interest in 3 month = 22x - 20x =2x
Let the annual interest rate = r %
( By the formula of simple interest rate )




Hence, the annual rate of interest = 40%
Simplifying the expression gives 13/ 36
<h3>How to solve the expression</h3>
Given;
1/4(1-2/3)^2+1/3
Represented as;

Take the LCM of the bracket

Find the square

Find the LCM

1 + 12/36
13/ 36
Thus, simplifying the expression gives 13/ 36
Learn more about fractions here:
brainly.com/question/1622425
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