Aisyah membeli 3 peniti dan 4 benang dengan harga Rp. 2.050,00. Sedangkan Khansa membeli 1 peniti dan 3 benang dengan harga Rp. 1.350,00. Harga 10 benang dan 5

x = peniti
y = benang

3x + 4y = 2050 | x1 (dikalikan 1)
x + 3y = 1350 |x3 (dikalikan 3)

3x + 4y = 2050
3x + 9y = 4050

dikurangi

-5y = -2000
y = 400

1 benang = 400 rupiah

x + 3y = 1350
x + 3 * 400 = 1350
x + 1200 = 1350
x = 1350 - 1200
x = 150

1 peniti = 150

10 benang = 10 * 400 = 4000
5 peniti = 5 * 150 = 750

jadi total harga 4.750 rupiah (B)

peniti = x
benang = y

3x + 4y =2.050 | 3| 9x + 12y = 6.150,00
1x + 3y = 1.350 | 4| 4x + 12y = 5.400,00 -
5x = 750,00
x = 750,00 / 5
= 150,00

1x + 3y = 1.350
1(150,00) + 3y = 1.350
150 + 3y = 1.350
3y = 1.350 - 150
y = 1.200/ 3
= 400

10x + 5y =
10(150) + 5(400)
1500 + 2000
3.500,00 (A)