Question

16 ≤ 4^x-1 < 1024

Answer 1

`16<= 4^(x-1)<1024`

` 4^2<= 4^(x-1)< 4^5`

`=>x=2-1=1`

`=>x=3-1=2`

`=>x=4-1=3`

vậy `x=1;2;3`