Answer :
[tex]\begin{cases} 5x+2y=9 \\ x+y=-3\end{cases} \\ \\\begin{cases} 5x+2*(-3-x)=9 \\ y=-3 -x\end{cases} \\ \\\begin{cases} 5x-6-2x =9 \\ y=-3 -x\end{cases}\\ \\\begin{cases} 3x =9+6 \\ y=-3 -x\end{cases}[/tex]
[tex]\begin{cases} 3x =15 \ \ /:3 \\ y=-3 -x\end{cases} \\ \\\begin{cases} x =5 \\ y=-3 -5\end{cases} \\ \\\begin{cases} x =5 \\ y=-8\end{cases}[/tex]
[tex]\begin{cases} 3x =15 \ \ /:3 \\ y=-3 -x\end{cases} \\ \\\begin{cases} x =5 \\ y=-3 -5\end{cases} \\ \\\begin{cases} x =5 \\ y=-8\end{cases}[/tex]
5x+2y=9 x+y=3
change x+y=3 into x=3-y
plug that equation into 5x+2y=9 where x is.
5(3-y)+2y=9
then distribute.
15-5y+2y=9
15-7y=9
minus 15.
-7y=-6
divide both sides by -7.
y is equal to -6/7.
then go back to the first equation and plug in for y.
and then you will get x.
then you will have (y,x)
