Tolong dijawab ya Kak please nomor 3, 4, dan 5 aja

3) misal : beras1 = x
beras2 = y
a. sistem persamaan x dan y
x + y = 50
6000x + 6200y = 306000
b. x + y = 50
x = 50 - y

6000x + 6200y = 306000
6000(50-y) + 6200y = 306000
300000-6000y+6200y = 306000
300000+200y = 306000
200y = 306000-300000
200y = 6000
y = 30

x = 50-y = 50 - 30 = 20
c. 4x = 4 . 20 = 80
7y = 7 . 30 = 210

4) misal: jam kerja asti = x
jam kerja anton = y
x + y = 16 => x = 16 - y

3x + 4y = 55
3(16-y) + 4y = 55
48-3y+4y = 55
48+y = 55
y=55-48
y=7

x=16-y=16-7=9

5) misal: karcis1 = x
karcis ll = y
x+y=500 => x = 500-y
8000x+6000y=2950000
8000(500-y) + 6000y = 2950000
4000000-8000y+6000y = 2950000
4000000-2000y = 29500000
-2000y = 2950000-4000000
-2000y = -1050000
y = 525

x = 500 - y = 500 - 525 = -25


maaf, yang nmr 5 aku nggak ketemu jawabannya..