Question

X+2y=12 3x-10y = 0 y=? x=?

Answer 1

$x+2y=12|\cdot5\\ 3x-10y=0\\\\ 5x+10y=60\\ \underline{3x-10y=0}\\ 8x=60\\ x=\dfrac{60}{8}=\dfrac{15}{2}\\\\ \dfrac{15}{2}+2y=12\\ 15+4y=24\\ 4y=9\\ y=\dfrac{9}{4}\\\\ \boxe{(x,y)=\left(\dfrac{15}{2},\dfrac{9}{4}\right)}$

Answer 2

$~~x+2y=12 \\ ~~3x-10y=0 \\ ~------ \\~ -3/x+2y=12 \\ ~~~~~~3x-10y=0 \\ ------- \\ -3x-6y=-36 \\ ~~~~3x-10y=0 \\ +------- \\ ~~~~-16y=-36 \\ \\ ~~~~y= \frac{36}{16}\rightarrow \boxed{\frac{9}{4}}$
$x+2. \frac{9}{4} =12 \\ \\ x+ \frac{18}{4} =12 \\ \\ \frac{4x+18}{4} =12 \\ \\ 4x+18=48 \\ 4x=30 \\ \\ x=\boxed{\frac{15}{2}}$