Question 874695
Let's equate the two expressions of y and solve for x.


{{{-x+3=2x+9}}}
{{{-x-2x=9-3}}}
{{{-3x=6}}}
{{{highlight(highlight(x=-2))}}}.


Your expected the WRONG answer for x.


Finding y:
{{{y=2(-2)+9}}}
{{{y=-4+9}}}
{{{highlight(y=5)}}}


The solution for these two equations is <b>(-2, 5)</b>.
The expected (2,13) is just plain wrong!