Question

encontre o conjunto solução dos sistemas de equações
-x+4y=9
2x-4y=-6
S=( 3,3 )

Answer 1

$\left \{ {{-x+4y=9} \atop {2x-4y=-6}} \right. \\\\\\ -x+4y=9\to -x=-4y+9(-1)\to x=4y-9\\\\\\\\ 2x-4y=-6\to 2(4y-9)-4y=-6\to 8y-18-4y=-6\to\\\\ 8y-4y=-6+18\to 4y=12\to y= \frac{12}{4} \to y=3\\\\\\\\ x=4y-9\to x=4*3-9\to x=12-9\to x=3\\\\\\\\\\ S=(3;3)$

Espero ter ajudado...