tentukan penyelesaian spldv berikut dengan metode substitusi a. x + 2y = 0 dan 2x - 3y = 7 b. y = x + 3 dan 2x + 3y = 4

a.
x+2y=0
x=-2y

2x-3y=7
2(-2y)-3y=7
-4y-3y=7
-7y=7
y=-1

x=-2y
x=-2(-1)
x=2

Hp={(2,-1)}

b.
y=x+3

2x+3y=4
2x+3(x+3)=4
2x+3x+9=4
5x+9=4
5x=4-9
5x=-5
x=-1

y=x+3
y=-1+3
y=2

Hp={(-1,2)}

Semoga bisa membantu...

MAPEL = MATEMATIKA
KELAS = 8
BAB = SPLDV

A.
x + 2y = 0 ➡ x = -2y
subtitusikan ke persamaan
2x - 3y = 7
2(-2y) -3y = 7
-4y - 3y = 7
-7y = 7
y = 7/-7
y = -1

subtitusi nilai y
2x - 3y = 7
2x - 3(-1) = 7
2x + 3 = 7
2x = 7 - 3
2x = 4
x = 4/2
x = 2

hp = {2,-1}

B.
y = x + 3
subtitusi ke persamaan
2x + 3y = 4
2x + 3(x + 3) = 4
2x + 3x + 9 = 4
5x = 4 - 9
5x = -5
x = -5/5
x = -1

subtitusi nilai x
y = x + 3
y = -1 + 3
y = 2

hp = {-1,2}