Hello!
Let's start with your original equation of x² = 17. To get the left side to just be x, you must perform to opposite operation being performed right now. In this case, the opposite of squaring a number is square rooting a number.
Therefore, when you square root both sides, you get:
[tex]x = ±\sqrt{17}[/tex]
The ± is there because the square root can be either positive or negative, as a negative number squared and a positive number squared both equal a positive number.
Now, to simplify, all you need to do is square root 17. There is no better way to do this than putting it in a calculator or memorizing it. When you do this, you get ±4.12310563, or roughly ±4.123.
Hope this helps!
