Answer:

Step-by-step explanation:
Given

Required
Find x
We have:

Rewrite as:

Expand

Factorize

Factor out x + 520

Split

Solve

Side length must be positive;
So:

I m getting 308.11, there is an additional 0.60 that is added, maybe your source is wrong, or there is a copying error.
Answer:
X=3.1
(4•3.1)+(4•3.1)
Step-by-step explanation:
4 of 6.2 is equal to 24.8
4•(6+0.2) = 24.8
4•3.1=12.4•2=24.8
12.4+12.4=24.8
(4x)+(4×)=24.8