Jika 4x+2y=2 dan 7x+4y=2,maka nilai 2x+5y=…

Bab Sistem Persamaan Linear Dua Variabel

4x + 2y = 2 [×2]
7x + 4y = 2 [×1]

8x + 4y = 4
7x + 4y = 2
_________ -
x = 2

4x + 2y = 2
4(2) + 2y = 2
2y = 2 - 8
y = -6/2
y = -3

2x + 5y
= 2(2) + 5(-3)
= 4 + (-15)
= -11

4x + 2y = 2 | ×2.
7x + 4y = 2 | × 1.

8x + 4y = 4.
7x + 4y = 2.
________-
x = 2.

8x + 4y = 4.
4y = 4 - 8x.
4y = 4 - 8(2).
4y = 4 - 16.
4y = -12.
y = -12/4.
y = -3.

= 2x + 5y.
= 2(2) + 5(-3).
= 4 + (-15).
= -11.