The equation is
.
Take square root on each side.
\

Subtract 3 from each side.
\
Apply additive inverse property:
.



Check:
\To check the solution substitute
in
.

Apply sum of squares formula:
.
\


Apply sum of squares formula:
.


Product of two different sings is negative.
\



The first solution
is true.
To check the solution substitute
in
.

Apply sum of squares formula:
.
\


Apply formula:
.

Product of two same sings is positive.
\
Product of two different sings is negative.
\



The second solution
is true.
The values of
.