Help me this exponent question please?

4^(x + 2) - 2^x * 8[2^(x - 1)]
= (2^2)^(x + 2) - 2^x * 2^3[2^(x - 1)]
= 2^[2(x + 2)] - 2^x * 2^[3 + (x - 1)]
= 2^(2x + 4) - 2^x * 2^(x + 2)
= 2^(2x + 4) - 2^(2x + 2)
= 2^(2x) * 2^4 - 2^(2x) * 2^2
= 2^(2x)(2^4 - 2^2)
= 2^(2x)(16 - 4)
= 2^(2x)(12)

2, 4, 8 are powers of 2.
Then use (a^m)^n = a^(mn).
And at the last use 2^x = 2^y then x=y. You can do it.
This is what happens when you forget formulae. Simple things become difficult.

4-4^x

If they want better, say screw you! I'm not einstein.

- SDFP!