Question

ME AJUDEM URGENTE!

1)determine o ponto de intersecção das retas r e s em cada um dos casos.

a)(r)x+2y-1=0 e (s)2x-y+3=0
b)(r)5x+y-3=0 e (s)2x+3y+17=0

Answer 1

a)

$\left \{ {{x+2y-1=0} \atop {2x-y+3=0}} \right. \\\\ \left \{ {{-2x-4y+2=0} \atop {2x-y+3=0}} \right.\\-5y=-5\\y=1\\\\x+2-1=0\\x=-1\\\\\boxed{P(-1,1)}$

b)

$\left \{ {{5x+y-3=0} \atop {2x+3y+17=0}} \right. \\\\ \left \{ {{-15x-3y+9=0} \atop {2x+3y+17=0}} \right. \\\\-13x=-26\\x=2\\\\5.2+y-3=0\\10+y-3=0\\y=-7\\\\\boxed{P(2,-7)}$