Log2(x-4)=4?

Question

Log2(x-4)=4?

Answer 1

I'm assuming that's log base 2 and you can't write a subscript. If that 's the case the rule is you take the base and raise it to the "answer" power and set that equal to the number/question in parentheses. So, 2^4=X-4; 16=x-4, so

X=20!

Hope this helps.

Answer 2

log base 2 or log base 10?

if base 2:

2^(log2(x-4)) = 2^4

2 and log base 2 cancels out

x-4 = 16

x = 20

if base 10:

10 ^ (log2(x-4)) = 10^4

10 and log cancels out

2(x-4) = 10000

2x - 8 = 10000

2x = 10008

x=5004