Question 990040
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{{{a^2+b^2+2ab-2a-2b}}} = {{{a^2+b^2+2ab}}} - {{{2*(a+b)}}} = {{{(a+b)^2}}} - {{{2*(a+b)}}} = {{{(a+b)}}}.{{{((a+b)-2)}}} = {{{(a+b)}}}.{{{(a+b-2)}}}.