1)
![\left \{ {{x=2y-8} \atop {x-4y=4}} \right. \\2y-8-4y=4\\y=-6\\x=2(-6)-8=-20 \left \{ {{x=2y-8} \atop {x-4y=4}} \right. \\2y-8-4y=4\\y=-6\\x=2(-6)-8=-20](https://tex.z-dn.net/?f=%5Cleft%20%5C%7B%20%7B%7Bx%3D2y-8%7D%20%5Catop%20%7Bx-4y%3D4%7D%7D%20%5Cright.%20%5C%5C2y-8-4y%3D4%5C%5Cy%3D-6%5C%5Cx%3D2%28-6%29-8%3D-20)
2)
\left \{ {{x=-8+5y} \atop {5x-4y=23}} \right. \\5(-8+5y)-4y=23\\y=3\\x=-8+5*3 = 7" alt="\left \{ {{5y-x=8} \atop {5x-4y=23}} \right. => \left \{ {{x=-8+5y} \atop {5x-4y=23}} \right. \\5(-8+5y)-4y=23\\y=3\\x=-8+5*3 = 7" align="absmiddle" class="latex-formula">