Question 802810


{{{-2z-xy=x+7}}}

{{{-2z-xy+xy=x+xy+7}}}

{{{-2z =x+xy+7}}}

{{{-2z-7 =x+xy+7-7}}}

{{{-2z-7 =x+xy }}}

{{{-2z-7 =x(1+y) }}}

{{{(-2z-7)/(1+y) =x }}}