Question

resolva os sistemas: { 6x + 2y = 10 {12y - 4x = 20

Answer 1

{ 6x + 2y = 10 => x= 10-2y/6
{12y - 4x = 20


12y - 4x = 20

12y-4.(10-2y/6)=20
12y-40+8y/6=20
72-40+8y= 120
8y+32= 120
8y= 120-32
8y= 88
y=88/8
y= 11

6x + 2y = 10
6x + 2. 11= 10
6x +22= 10
6x= 10 -22
6x= -12
x= -12/6
x= -2


PROVA REAL:

6x + 2y = 10
6.(-2)+2.11=10
-12+22=10
10=10