tolong d bantu y kak!!! 1. persamaan 3x+y=19 dan 4x-2y=12, tentukan nilai x dan y dengan menggunakan a.) metode eliminasi b.) metode subtitusi 2. persamaan 2x+y

1. substitusi :
3x+y = 19 | x2 <=> 6x+2y = 38
4x-2y = 12 | x 1 <=> 4x-2y = 12
------------------ +
10x = 50
x = 5
eliminasi
3x+y =19
3(5) + y = 19
15 + y = 19
y = 19 - 15
y = 4

1)
a) Eliminasi
3x + y = 19 《×2》
4x – 2y = 12《×1》

6x + 2y = 38
4x – 2y = 12
__________ +
10x = 50
x = 5

3x + y = 19 《×4》
4x – 2y = 12《×3》

12x + 4y = 76
12x – 6y = 36
___________ _
10y = 40
y = 4

b) Substitusi
3x + y = 19 → x = 19 – y / 3
4x – 2y = 12

4 (19 – y / 3) – 2y = 12
76 – 4y / 3 – 2y = 12
76 – 4y – 6y = 36
76 – 10y = 36
–10y = 36 – 76
–10y = –40
y = 4

3x + y = 19
3x + 4 = 19
3x = 19 – 4
3x = 15
x = 5

2)
2x + y = 5 {×2}
3x – 2y = 4 {×1}

4x + 2y = 10
3x – 2y = 4
_________ +
7x = 14
x = 2

2x + y = 5
2(2) + y = 5
4 + y = 5
y = 5 – 4
y = 1

a)
x²y = 2² · 1 = 4
b)
2xy = 2(2)(1) = 4

Semoga membantu.