Question 872441
<pre>
{{{16^(x+4)}}}{{{""=""}}}{{{64^(x+1)}}}

16 and 64 are both powers of 4

So we write 16 as 4² and 64 as 4³

{{{(4^2)^(x+4)}}}{{{""=""}}}{{{(4^3)^(x+1)}}}

Remove the parentheses by multiplying the exponents:


{{{4^(2(x+4))}}}{{{""=""}}}{{{4^(3(x+1))}}}

Equal exponentials with the same positive base &#8800; 1 
have equal exponents:

{{{2(x+4)}}}{{{""=""}}}{{{3(x+1)}}}

{{{2x+8}}}{{{""=""}}}{{{3x+3}}}

{{{5}}}{{{""=""}}}{{{x}}}

Edwin</pre>