Question

jika x dan y merupakan penyelesaian sistem persamaan x - 2y = -12 dan 3x + 2y = -8 ,maka nilai 2x + 3y =?
pake cara yaahh :)​

Answer 1

SPLDV

Eliminasi y.

x - 2y = -12

3x + 2y = -8

_________-

x - 3x = -12 - (-8)

-2x = -4

  x = 4/2

  x = 2

Substitusi x.

x - 2y = -12

2 - 2y = -12

2 + 12 = 2y

2y = 14

 y = 14/2

 y = 7

Maka:

2x + 3y = 2(2) + 3(7) = 4 + 21 = 25

Jadi, nilai 2x + 3y adalah 25.

Answer 2

x - 2y = -12. |×3| = 3x - 6y = -36

3x + 2y = -8 |×1| 3x + 2y = -8

___________-

-8y = -28

y = 3,5 cm

3x + 2y = -8

3x + 7 = -8

3x = -15

x = -5

2x + 3y

-10 + 10,5

0,5