tentukan himpunan penyelesaian sistem persamaan berikut! 3. a-2b=2 dan 3b-5a=4 8.5c-2d=4 dan 4c+d=11 9.5g-2h=4 dan 3g=4h-6 10.2r+3s=18 dan 3r+2s=17 tolong diban

#3
a - 2b = 2
a = 2 + 2b

3b - 5a = 4
3b - 5(2 + 2b) = 4
3b - (10 + 10b) = 4
3b - 10 - 10b = 4
3b - 10b = 4 + 10
(-7)b = 14
b = (-2)

a = 2 + 2b
= 2 + (-4)
= (-2)

#8
4c + d = 11
d = 11 - 4c

5c - 2d = 4
5c - 2(11 - 4c) = 4
5c - 22 - 8c = 4
-4 + (-22) = 8c - 5c
-26 = 3c
c = 8,667

d = 11 - 4c
= 11 - 34,667
= -23,667

#9
5g - 2h = 4
15g - 6h = 12
5(4h - 6) - 6h = 12
20h - 30 - 6h = 12
20h - 6h = 12 + 30
14h = 42
h = 3

3g = 4h - 6
= 12 - 6
= 6
g = 2

#10
2r + 3s = 18
2r = 18 - 3s
r = 9 - 3/2s

3(9 - 3/2s) + 2s = 17
27 - 9/2s + 2s = 17
54/2 - 9/2s + 4/2s = 34/2
54 - 9s + 4s = 34
54 - 34 = 9s - 4s
20 = 5s
s = 4

r = 9 - 3/2s
= 9 - 6
= 3