1. x+y=1 dan x+5y=5 2. 3x+2y=12 dan 2x-y=8 3.2x+y=5 dan 3x-2y=4 Dengan cara eliminasi dan substitusi... please esok kumpul..

1. eliminasi :
    x+y  =1                                                    x+y=1
    x+5y=5 -                                                 x+1=1
__________                                               x=o
  (otomatis x hilang karena dikurang)
  -4y=-4
    y=1     
   

1.

Eliminasi x
x + y = 1
x + 5y = 5
________-
-4y = -4
y = -4/-4
y = 1

x + y = 1
x + 1 = 1
x + 1 - 1 = 1 - 1
x = 0


x = 0
y = 1


2.

3x + 2y = 12
2x - y = 8

Eliminasi x
3x + 2y = 12 | x 2| 6x + 4y = 24
2x - y = 8 | x 3| 6x - 3y = 24

6x + 4y = 24
6x - 3y = 24
__________-
7y = 0
y = 0

2x - y = 8
2x - 0 = 8
2x = 8
x = 8/2
x = 4

x = 4
y = 0


3.

2x + y = 5
3x - 2y = 4

Eliminasi x
2x + y = 5 | x 3| 6x + 3y = 15
3x - 2y = 4 | x 2| 6x - 4y = 8

6x + 3y = 15
6x - 4y = 8
_________-
7y = 7
y = 7/7
y = 1

2x + y = 5
2x + 1 = 5
2x + 1 - 1 = 5 - 1
2x = 4
x = 2

x = 2
y = 1


1. Substitusi x + y = 1 x = 1 - y Memasuki x ke pers 2 x + 5y = 5 (1 - y) + 5y = 5 1 + 4y = 5 1 - 1 + 4y = 5 - 1 4y = 4 y = 4/4 y = 1 x = 1 - y x = 1 - 1 x = 0 x = 0 y = 1 2. Substitusi 2x - y = 8 - y = 8 - 2x y = (8 - 2x)/-1 y = - 8 + 2x Memasuki y ke pers 1 3x + 2y = 12 3x + 2(-8 + 2x) = 12 3x - 16 + 4x = 12 3x + 4x - 16 + 16 = 12 + 16 7x = 28 x = 4 y = -8 + 2x y = -8 + 2(4) y = -8 + 8 y = 0 x = 4 y = 0 3. Substitusi 2x + y = 5 y = 5 - 2x Memasuki y ke pers 2 3x - 2(5 - 2x) = 4 3x - 10 + 4x = 4 3x + 4x - 10 + 10 = 4 + 10 7x = 14 x = 2 y = 5 - 2x y = 5 - 2(2) y = 5 - 4 y = 1 x = 2 y = 1 Maaf kalau salah...