Question

resolva os sistemas. a) {2x+y-4=0 {x+2(x-y)=-1

Answer 1

2x + y -4 =0 x+2(x-y)= -1
y = 4 - 2x x +2x - 2y = -1
y= 4 - 2×1 3x - 2(4 - 2x) = -1
y= 4 - 2 3x -8 + 4x = -1
y= 2 b 7x = -1 +8
x = 7/7
x= 1