Answer:

Explanation:
First, move the constant term to the other side of the equation.


Next, add the coefficient of the first degree j term divided by 2, then squared to both sides.




Now, we can factor the left side as a square.


Finally, we can take the square root of both sides to solve for j.



Note that there are two solutions, as
could be positive OR negative because of the even root property:
if
,
then

because both
and
equal
.