Question 781449
{{{(u-4)^2 =18}}}<P>
{{{u-4 = sqrt(18) = sqrt(9*2) = 3*sqrt(2)}}} or {{{u-4 = -sqrt(18) = -sqrt(9*2) = -3*sqrt(2)}}}<P>
{{{u = 4+3sqrt(2)}}} or {{{u=4-3sqrt(2)}}}