Diketahui sistem persamaan 2x – 3y = -18 dan 4x – y = -16. Nilai 5x + 2y adalah… (tolong banget ya, sekalian tulisin caranya. makasih)
2x – 3y = -18 -> 4x – 6y = -36
4x – y = -16 -> 4x – y = -16 –
-5y = -20
y = 4
4x – y = -16
4x – 4 = -16
4x = -12
x = -12 : 4
x = -3
nilai 5x +2y = 5 x (-3) + 2 x 4
= -15 + 8
= -7