Question

Tentukanlah nilai x dan y dari persamaan berikut :
A.2x-4y=14
2y=-13-x
B.1/2x-2/3y=1
1/4x+1/6y=-1
C.x-1/3y=5/6
1/3x-1/4y=5/12
D.3(x+2)-2(y+3)=8
5(x+2)+3(y+3)=45

keterangan :
/=per
misal 1/2=1:2
=0.5
PAKE CARANYA YA !!!

Answer 1

A. 2x-2.2y=14
2x-2(-13-x)=14
2x+26+2x=14
4x=14-26
4x=-12
x=-3
2y=-13-x
2y=-13-(-3)
2y=-13+3
2y=-10
y=-5

b.½x+⅔y=1 |x6
3x+4y=6 .......(1)
¼x+1/6y=-1 |x12
3x+2y=-12 ......(2)
(1)-(2)
2y=18
y=9
3x+4y=6
3x+4.9=6
3x=6-36
3x=-30
x=-10

c.x-⅓y=5/6 |x6
6x-2y=5 ....(1)
⅓x-¼y=5/12 |x12
4x-3y=5 .....(2)
(1)x2 -> 12x-4y=10 .... (3)
(2)x3 -> 12x-9y=15 ....(4)
(3)-(4)
5y=-5
y=-1
4x-3y=5
4x-3(-1)=5
4x+3=5
4x=5-3
4x=2
x=½

d. 3x+6-2y-6=8
3x-2y=8 ...(1)
5x+10+3y+9=45
5x+3y+19=45
5x+3y=45-19
5x+3y=26 ....(2)
(1)x3 -> 9x-6y=24
(2)x2 -> 10x+6y=52
(1)+(2)
19x=76
x=4
3x-2y=8
3.4-2y=8
-2y=8-12
-2y=-4
y=2

semoga bisa membantu dan bisa dipahami :)