Question

Bài `3` ạ

  

Answer 1

Bài 3: 

a: =>6^x=6²

hay x=2

b: =>(2x-1)²=25

=>2x-1=5 hoặc 2x-1=-5

=>2x=6 hoặc 2x=-4

=>x=3 hoặc x=-2

c: \(\Leftrightarrow4^{x+3}=5^5\)

=>x+3=5

hay x=2

d: \(\Leftrightarrow7^x=49\)

hay x=2

Answer 2

`3)`

`a)6^x = 36`

`6^x=6^2`

`x=2`

`b)2.(2x-1)^2=50`

`(2x-1)^2=50:2`

`(2x-1)^2=25`

`+` Trường hợp `1` `:`

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

`2x-1=5`

`2x=5+1`

`2x=6`

`x=3`

`+` Trường hợp `2` `:`

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

`2x-1= -5`

`2x= -5+1`

`2x= -4`

`x= -2`

Answer 3

`c)64.4^x=4^5`

`4^3 . 4^x =4^5`

`4^x=4^5:4^3`

`4^x=4^2`

`x=2`

`d) 49.7^x=2401`

`7^2 . 7^x= 7^4`

`7^(2+x)=7^4`

`2+x=4`

`x=2`