Solve 2^x=128

$$2 ^ { x } = 128$$

Solve for x

$$x=7$$

Steps Using Definition of Logarithm

Use the rules of exponents and logarithms to solve the equation.

$$2^{x}=128$$

Take the logarithm of both sides of the equation.

$$\log(2^{x})=\log(128)$$

The logarithm of a number raised to a power is the power times the logarithm of the number.

$$x\log(2)=\log(128)$$

Divide both sides by \log(2).

$$x=\frac{\log(128)}{\log(2)}$$

By the change-of-base formula \frac{\log(a)}{\log(b)}=\log_{b}\left(a\right).

$$x=\log_{2}\left(128\right)$$

Solve for x (complex solution)

$$x=\frac{2\pi n_{1}i}{\ln(2)}+7$$

$$n_{1}\in \mathrm{Z}$$