Question

Tìm x:

a)  1 5 27 + 3 x − 7 9 3 = 24 27

b)  2 x − 1 2 = 3 4

c)  2 x − 1 3 + 5 6 = 1

Answer 1

a)

1 5 27 + 3 x − 7 9 3 = 24 27 3 x − 7 9 3 = 24 27 − 1 5 27 3 x − 7 9 3 = − 8 27 3 x − 7 9 = − 2 3 3 x = 1 9 x = 1 27

b)

2 x − 1 2 = 3 4 2 x = 5 4 x = 5 8 x = ± 5 8

c) 

2 x − 1 3 + 5 6 = 1 2 x − 1 3 = 1 6 2 x − 1 3 = ± 1 6

TH1:

2 x − 1 3 = 1 6 2 x = 1 2 x = 1 4

TH2:

2 x − 1 3 = − 1 6 2 x = 1 6 x = 1 12

Vậy  x = 1 4 hoặc x = 1 12