~SPLDV

DIKETAHUI:

• 4x + 5y = 4.550
• 2x + 3y = 2.550

DITANYA:

• Nilai dari x + 2y = …?

JAWAB:

— Metode Substitusi

» 4x + 5y = 4.550 (pers. 1)

» 2x + 3y = 2.550 (pers. 2)

› Evaluasi pers. 2

» 2x + 3y = 2550

» 2x = 2.550 - 3y

» x = 2.550/2 - 3/2 y

» x = 1275 - 3/2 y

› Substitusi pers. 2 ke pers. 1

» 4x + 5y = 4.550

» 4(1275 - 3/2 y) + 5y = 4.550

» 4×1275 - 4×3/2 y + 5y = 4.550

» 5.100 - 6y + 5y = 4.550

» 5.100 - y = 4.550

» -y = 4.550 - 5.100

» -y = -550

» y = 550

› Substitusi nilai y ke pers. 2

» x = 1275 - 3/2 y

» x = 1275 - 3/2 × 550

» x = 1275 - 1650/2

» x = 1275 - 825

» x = 450

HP = {450 , 550}

---

= x + 2y

= 450 + 2 × 550

= 450 + 1.100

= 1.550 ✓

KESIMPULAN:

Jadi, nilai x + 2y dari sistem persamaan linear dua variabel 4x + 5y = 4.550 dan 2x + 3y = 2.550 adalah 1.550 .