Question 195720
{{{(xy-ab-8)-(xy-3ab-1)}}} Start with the given expression.



{{{xy-ab-8-xy+3ab+1}}} Distribute



{{{(xy-xy)+(-ab+3ab)+(-8+1)}}} Group like terms.



{{{0xy+2ab-7}}} Combine like terms.



{{{2ab-7}}} Simplify.



So {{{(xy-ab-8)-(xy-3ab-1)=2ab-7}}}