Question

resolva o sistema :x+2y=-12
3x+8y=31

Answer 1

{ X + 2Y = - 12 i) { X = -12-2Y iii) { X = -12-2(33.5) => X = -79

=>

{ 3X + 8Y = 31 ii) { 3(-12-2Y) + 8Y = 31 => -36-6Y + 8Y = 31 =? 2Y = 31+36 =>

Y = 33.5