Question 130663
{{{4^x+5=12}}} Start with the given equation. 



{{{4^x=7}}} Subtract 5 from both sides



{{{log(10,(4^x))=log(10,(7))}}} Take the log of both sides



{{{x*log(10,(4))=log(10,(7))}}} Rewrite the left side using the identity  {{{log(b,(x^y))=y*log(b,(x))}}}



{{{x=log(10,(7))/log(10,(4))}}} Divide both sides by {{{log(10,(4))}}}



{{{x=log(4,(7))}}} Use the change of base formula to simplify the right side