Question

can you show me how to solve this problem: a. ) 16=4 to the 3rd power x -7

Answer 1

We assume you mean
$\ \ \display{16=4^{3x-7}}$
This is solved by writing 16 as a power of 4 and equating exponents.
$\ 4^{2}=4^{3x-7}$
  2 = 3x - 7 . . . . . equate exponents
  9 = 3x . . . . . add 7
  3 = x . . . . . divide by 3

The solution is x = 3.