Đáp án`+`Giải thích các bước giải:

 `a, 3^(x - 1)  + 5.3^(x -1) = 162`

`=> 3^(x - 1) (1 + 5) = 162`

`=> 3^(x - 1) .6 = 162`

`=> 3^(x - 1) = 27`

`=> 3^(x - 1) = 3^3`

`=> x - 1 =3`

`=> x = 4`

Vậy `x = 4`

`b, 5^x + 5^(x + 2) = 650`

`=> 5^x . (1 + 5^2) = 650`

`=> 5^x . 26 =650`

`=> 5^x = 25`

`=> 5^x = 5^2`

`=> x= 2`

Vậy `x  = 2`

c, 2.2^(2x) + 4^3 . 4^x = 1056`

`=> 2. 2^(2x) + 4^3 . (2^2)^x=  1056`

`=> 2.  2^(2x) + 64 . 2^(2x) = 1056`

`=> 2^(2x) . (2 + 64) = 1056`

`=> 2^(2x) .  66 = 1056`

`=> 2^(2x) = 16`

`=> 2^(2x) = 2^4`

`=> 2x = 4`

`=> x = 2`

Vậy `x = 2`

`d, 3^(x - 1) + 5. 3^(x - 1) = 486`

`=> 3^(x - 1) . (1 + 5) = 486`

`=> 3^(x - 1) . 6 = 486`

`=> 3^(x - 1) = 81`

`=> 3^(x - 1) = 3^4`

`=> x - 1= 4`

`=> x = 5`

Vậy `x = 5`

`e, 2^(-1) . 2^x+  4. 2^x = 9 . 2^5`

`=> 2^x . (2^(-1) + 4) = 9 . 2^5`

`=> 2^x . 9/2 = 9 . 2^5`

`=> 2^x = 2^6`

`=> x =6`

Vậy `x =6`

`f, 4^(x - 2) + 4^(x +1) = 1040`

`=> 4^(x - 2) . (1 + 4^3) = 1040`

`=>4^(x - 2).  65 = 1040`

`=> 4^(x - 2) = 16`

`=> 4^(x - 2) = 4^2`

`=> x - 2= 2`

`=> x = 4`

Vậy `x= 4 `

`***`sharksosad