Question 1015741
Parallel to 2x-7y=3 means the wanted line must have the same slope.
{{{-7y=-2x+3}}}
{{{y=(2/7)x-3/7}}}
NEED slope {{{2/7}}} but the needed equation is  {{{y=(2/7)x+b}}}.


MUST contain  (1,2).
{{{(2/7)*1+b=2}}}
{{{b=2-2/7}}}
{{{b=14/7-2/7}}}
{{{b=12/7}}}
-
{{{y=(2/7)x+12/7}}}
{{{-(2/7)x+y=12/7}}}
{{{-2x+7y=12}}}--------but you want the constant term of the RIGHT member to be 7 because
the specified form was given as Ax+By=7.


{{{(-2x+7y)(7/12)=12(7/12)}}}
{{{highlight(highlight(-(7/6)x+(49/12)y=7))}}}


{{{highlight(system(A=-7/6,B=49/12))}}}