giuppppppppppppppppppppppppppppp

`a)`

`5^x .5^(x+1) .5^(x+2) =1000...0:2^15 (15`$c/s$ `0)`

`=>5^(x+x+1+x+2)=10^15 :2^15`

`=>5^(3x+3)=5^15`

`=>3x+3=15`

`=>3x=15-3`

`=>3x=12`

`=>x=12:3`

`=>x=4`

Vậy `x=4`