Question 1120929
d, Doris
x, Sister


{{{system(d=x+3,d+2=3(x-1))}}}

-

{{{x+3+2=3x-3}}}
{{{x+5=3x-3}}}
{{{8=2x}}}
{{{highlight(x=4)}}}
-
{{{highlight(d=7)}}}