The problem 8^x = 16^x+2 the choices a)8 and b)-8. Help please!

Given that information I want to say the answer is -8 ?

where is the 2. Use parentheses.
Is it 16x+2 or 16x+2

The 2 is part of the exponent.

Take the log of both sides.
log 8x=log 16x+2
x*log 8 = x+2*log 16
solve for x

Perhaps I should have used parentheses, too.
x*log 8 = (x+2)*log 16.