For this case we have the following equation:

We apply distributive property on the left side of the equation:

We simplify the left side of the equation:

Different signs are subtracted and the major sign is placed.

On the right side we must take into account that:

So:

We add x to both sides of the equation:

We subtract 2 from both sides of the equation:

We multiply by 3 on both sides of the equation:

We divide by 8 on both sides of the equation:

Thus, the solution of the equation is:

Answer:

This is an iteration method for finding the square root.
The ? is also your first initial guess.
? = 10.5
The iteration formula for the square root is actually.
√n = (x + n/x)÷2.
Where x is your guess.