```Question 131556
{{{x - 2y = 9}}}
{{{1.5x + 0.5y = 6.5}}}

I presume you took the first equation and did something like {{{x=2y+9}}}

All you have to do is replace x in the second equation with 2y + 9 and then solve for y.

{{{cartoon(red(1.5x) + 0.5y = 6.5,red(1.5(2y+9)) + 0.5y = 6.5)}}}

{{{1.5(2y+9) + 0.5y = 6.5}}}
{{{3y+13.5+0.5y=6.5}}}
{{{3.5y+13.5=6.5}}}
{{{3.5y=6.5-13.5}}}
{{{3.5y=-7}}}
{{{y=-2}}}

Now that you know that {{{y=-2}}}, you can substitute that value into either of the equations so that you can solve for x.

{{{cartoon(x - red(2y) = 9,x-red(2(-2))=9)}}}

{{{x+4=9}}}
{{{x=5}}}

So the solution set is the ordered pair (5,-2).

Check your answer by substitution, the ordered pair coordinates should make both equations true statements:

{{{5-(-2)=9}}},{{{9=9}}} True
{{{1.5(5) + 0.5(-2) = 6.5}}}, {{{7.5-1=6.5}}}, {{{6.5=6.5}}} True.

You can also graph both lines to see if they intersect at (5,-2)

{{{drawing(400,400,-10,10,-10,10,
grid(1),
graph(400,400,-10,10,-10,10,x/2-9/2,-3x+13),
locate(5,-2,S(5,-2)),
circle(5,-2,.1)
)}}}```