Question 1076100


{{{28x-2x^2=26 }}}.....move all terms from the left to the right

{{{0=2x^2-28x+26 }}}..........group

{{{0=(2x^2-28x)+26 }}}.....factor out {{{2}}} 

{{{0=2(x^2-14x)+26 }}}.........recall {{{(a+b)^2=a^2+2ab+b^2}}}; so, we need {{{b}}} part to complete our square

{{{0=2(x^2-14x+b^2) -2*b^2+26 }}}........since  {{{a=1}}} and  {{{2ab=14}}}, we use it to calculate {{{b}}}

{{{2ab=14}}}=>{{{2*1b=14}}}=>{{{b=14/2}}}=>{{{b=7}}}

plug it in

{{{0=2(x^2-14x+7^2) -2*7^2+26 }}}

{{{0=2(x-7)^2-2*49+26 }}}

{{{0=2(x-7)^2-98+26 }}}

{{{0=2(x-7)^2 -72 }}}