Question 19560
{{{2^(1-x) = 19}}} Take the log of both sides.
{{{(1-x)log2 = log19}}} Divide both sides of the equation by log2
{{{1-x = (log19)/(log2)}}} Add x to both sides.
{{{1 = (log19)/(log2) + x}}} Subtract {{{(log19)/(log2)}}} from both sides.
{{{1 - (log19)/(log2) = x}}} Evaluate.
{{{x = 1 - 4.2479}}}
{{{x = -3.2479}}}

Check:

{{{2^(1-(-3.2479)) = 2^4.2479}}} = {{{18.9996}}}