Skip to main content
Solve for x
Tick mark Image
Solve for x (complex solution)
Tick mark Image
Graph

Similar Problems from Web Search

Share

9\times 3^{-x+1}=81
Use the rules of exponents and logarithms to solve the equation.
3^{-x+1}=9
Divide both sides by 9.
\log(3^{-x+1})=\log(9)
Take the logarithm of both sides of the equation.
\left(-x+1\right)\log(3)=\log(9)
The logarithm of a number raised to a power is the power times the logarithm of the number.
-x+1=\frac{\log(9)}{\log(3)}
Divide both sides by \log(3).
-x+1=\log_{3}\left(9\right)
By the change-of-base formula \frac{\log(a)}{\log(b)}=\log_{b}\left(a\right).
-x=2-1
Subtract 1 from both sides of the equation.
x=\frac{1}{-1}
Divide both sides by -1.