Answer :
[tex]~~x+2y=12 \\ ~~3x-10y=0 \\
~------ \\~ -3/x+2y=12 \\ ~~~~~~3x-10y=0 \\ ------- \\ -3x-6y=-36 \\ ~~~~3x-10y=0 \\ +------- \\ ~~~~-16y=-36 \\ \\ ~~~~y= \frac{36}{16}\rightarrow \boxed{\frac{9}{4}} \\ \\[/tex]
[tex]x+2. \frac{9}{4} =12 \\ \\ x+ \frac{18}{4} =12 \\ \\ \frac{4x+18}{4} =12 \\ \\ 4x+18=48 \\ 4x=30 \\ \\ x=\boxed{\frac{15}{2}}[/tex]
[tex]x+2. \frac{9}{4} =12 \\ \\ x+ \frac{18}{4} =12 \\ \\ \frac{4x+18}{4} =12 \\ \\ 4x+18=48 \\ 4x=30 \\ \\ x=\boxed{\frac{15}{2}}[/tex]
[tex]x+2y=12|\cdot5\\
3x-10y=0\\\\
5x+10y=60\\
\underline{3x-10y=0}\\
8x=60\\
x=\dfrac{60}{8}=\dfrac{15}{2}\\\\
\dfrac{15}{2}+2y=12\\
15+4y=24\\
4y=9\\
y=\dfrac{9}{4}\\\\
\boxe{(x,y)=\left(\dfrac{15}{2},\dfrac{9}{4}\right)}[/tex]