Question

SPLDV 2x + y = 120 dan x + 2y = 105 . Tentukan 5x + 3y

Answer 1

2x + y = 120 |×1| 2x + y = 120
x + 2y = 105 |×2| 2x + 4y = 210 -
- 3y = - 90
y = 30
Subtitusi y = 30 ke pers (1)
2x + 30 = 120
2x = 120 - 30
2x = 90
x = 45
Jadi, 5x + 3y = 5×45 + 3×30 = 225 + 90 = 315