Question 961520
Expand the right hand side,
{{{2u^2-21u+55=u^2-14u+49}}}
{{{u^2-7u+6=0}}}
{{{(u-1)(u-6)=0}}}
Two solutions:
{{{u-1=0}}}
{{{u=1}}}
and
{{{u-6=0}}}
{{{u=6}}}