50 kilogram beras a dan 40 kilogram beras b harganya 500.000. 30 kilogram beras a dan 20 kilogram beras b harganya 280.000. Tentukan: a. Harga 1 kilogram beras

b). 50a + 40b = 500.000 | x 30
30a + 20b = 280.000 | x 50
= 1500a + 1200b = 15000000
1500a + 1000b = 14000000 _
= 200b = 1000000
b = 5000

a). 50a + 40(5000) = 500000
50a + 200000 = 400000
a = 4000

c). 1a + 1b
4000 + 5000 = 9000