Question

identifique as coordenadas de P (x, y) que é um ponto comum as retas (r) 6x+2y-20=0 e (s) 2x+12y+16=0

Answer 1

$\left \{ {{6x+2y=20} \atop {2x+12y=-16}} \right.\\ Vamos multiplicar (s) por (-3)\\ \left \{ {{6x+2y=20} \atop {-6x-36y=48}} \right.\\ \left \{ {{{-34y=68}} \right.\\ \left \{ {{{y= \frac{68}{-34} }} \right.\\ \left \{ {{{y=-2}} \right.\\ \left \{ {{6x+2y=20} \atop {-6x-36y=48}} \right.\\ \left \{ {{{-34y=68}} \right.\\ (r) 6x+2(-2)-20=0\\ (r) 6x = 20 +4\\ (r) x = \frac{24}{6}\\ (r) x = 4 \\P = (4,-2 )$