please solve i got 3 but i’m not sure

Short answer x = 11/3
Step One
Change 64 to a power of 4
[tex] \text{64 = 4}^{4} [/tex]

Step Two
Include 2x - 4 as part of your power. So far you are only working on the right side of the problem.

[tex] (x^{4*(2x - 4)} [/tex]

Step Three
The bases are the same so you can equate the powers.
2x + 6   = 4(2x - 4) 

Step Four
Remove the brackets on the right.
2x + 6 = 8x - 16 

Step five
Collect like terms.     Begin by adding 14 to both sides.
2x + 6 + 16 = 8x       Subtract 2x from both sides.
22 = 8x - 2x
22 = 6x                     Divide by 6
22/6 = x
x = 3.666333 or 3 2/3 or 11/3

Check
Left hand side
4^(2*11/3 + 6) 
4^(22/3 + 6)
4^(22/3 + 18/3)
4^(40/3) 

Right Side
64^(2*11/3 - 4)
64^(22/3 - 4)
64^(22/3 - 12/3)
64^(10/3)    There is something we can do without figuring out what this is.
64 = 4^4
4^(4*10/3)
4^(40/3) which is the same as the left side

Answer x = 11/3 <<<<<