Respuestas
1) 5x-y = 9 5x - 9 = y
2x+y = 12 y = 12 - 2x
5x - 9 = 12 - 2x
7x = 21
x= 3
y = 12 -2(3) = 6
y = 6
2) 4x+2y = 26 y = 13 - 2x
x+3y=14 y = 14 -x / 3
13 - 2x = 14 -x / 3
39 - 6x = 14 - x
25 = 5x
x= 5
y = 13- 2(5)= 3
y= 3
3) x+y = -8 y = -8 -x
x-y = -2 x-2 = y
-8 -x =x-2
-6 = 2x
x= -3
-3 +y = -8
y = -5
4) x+2y = 2 y = 2- x / 2
-2x+3y = 10 y = 10+ 2x / 3
2- x / 2 = 10+ 2x / 3
6 -3x = 20 + 4x
-7x = 14
x= -2
y = 10+ 2(-2) / 3
y = 2
5) x+3y = 5 y = 5 -x / 3
5x-4y = 6 y = 5x -6 / 4
5 -x / 3 = 5x -6 / 4
20 - 4x = 15x -18
38 = 19x
x= 2
y = 5- 2/3
y= 1
1) 3x+7y = -17 x = -17 -7y / 3
5x-2y = -1
5( -17 -7y / 3) -2y = -1
-85 -35y -6y = -3
-82 = 41y
y= -2
x = -17 -7(-2) / 3
x = -1
2) 2x+y = 16 y= 16-2x
3x-3y = 6
reemplazando
3x - 3(16-2x) = 6
3x -48 +6x = 6
9x = 54
x= 6
y= 16-2(6)
y= 4
3) 3x-2y = -2 x = -2 +2y / 3
x+y = 6
reemplazando
-2 +2y / 3 + y = 6
-2 +2y+3y = 18
5y = 20
y = 4
x = -2 +2( 4) / 3
x= 2
4) 5x+2y = 40 x= 40 -2y / 5
-2x-5y = 26
reemplazando
-2(40 -2y / 5) -5y = 26
-80 +4y -25y = 130
-21y = 210
y= -10
x= 40 -2(-10) / 5
x= 12
5) 2x+3y = 13 x= 13 -3y / 2
4x-y = 5
reemplazando
4( 13 -3y / 2) -y = 5
26 -6y -y =5
21 = 7y
y = 3
x= 13 -3 (3) / 2
x= 2
guiate we