The formula of an area of a square:

a - a side
We have 
substitute:

Used:

28x=168
x=6
that is the answer I guess
Answer:
Rewriting the expression
with a rational exponent as a radical expression we get ![\mathbf{\sqrt[9]{3} }](https://tex.z-dn.net/?f=%5Cmathbf%7B%5Csqrt%5B9%5D%7B3%7D%20%7D)
Step-by-step explanation:
We need to rewrite the expression
with a rational exponent as a radical expression.
The expression given is:

First we will simply the expression using exponent rule 

As we know 2 and 18 are both divisible by 2, we can write

Now we know that ![a^\frac{1}{9}=\sqrt[9]{a}](https://tex.z-dn.net/?f=a%5E%5Cfrac%7B1%7D%7B9%7D%3D%5Csqrt%5B9%5D%7Ba%7D)
Using this we get
![=\sqrt[9]{3}](https://tex.z-dn.net/?f=%3D%5Csqrt%5B9%5D%7B3%7D)
So, rewriting the expression
with a rational exponent as a radical expression we get ![\mathbf{\sqrt[9]{3} }](https://tex.z-dn.net/?f=%5Cmathbf%7B%5Csqrt%5B9%5D%7B3%7D%20%7D)
Answer:
(x+1)+(3x+1)+(2x+4)=180 (sum od all sode of a triangle is 180)
x+1+3x+1+2x+4=180
6x+6=180
6x=180-6
x=174/6
x=66