Tentukan himpunan penyelesaian dari sistem persamaan berikut dengan metode substitusi jika x, y variabel pada himpunan bilangan real. a.) x = y + 2 dan y = 2x

Bab SPLDV
Matematika SMP Kelas VIII

a] x = y + 2
x = 2x - 5 + 2
x - 2x = -3
-x = -3
x = 3

y = 2x - 5
y = 2 . 3 - 5
y = 6 - 5
y = 1

HP = {(3, 1)}

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

y = -x
y = -1

HP = { (1, -1) }

c] x + y = 1
y = 1 - x

2x + 3y = 0
2x + 3 (1 - x) = 0
2x + 3 - 3x = 0
-x = -3
x = 3

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

HP = { (3, -2) }

a.

x =>> y + 2
x =>> 2-5
x =>> - 3

y [>> 2x - 5
y [>> 2.3 -5
y [>> 6-5
y [>> 1

b.

y =>> -x
y =>> -x - 1
y [>> -x1

2 =>> 3x + 2
3x =>> 2-2
3x [>> 0
x =>> 0

c.

0 [>> 2x + 3y
2x =>> 3y - 0
2x =>> 3y
x =>> 3y/2

1 =>> x + y
y =>> x-1

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