Algebra Examples

$\log_{\frac{1}{2}} (8)$

Step 1

Rewrite as an equation.

$\log_{\frac{1}{2}} (8) = x$

Step 2

Rewrite $\log_{\frac{1}{2}} (8) = x$ in exponential form using the definition of a logarithm. If $x$ and $b$ are positive real numbers and $b$ does not equal $1$ , then $\log_{b} (x) = y$ is equivalent to $b^{y} = x$ .

${(\frac{1}{2})}^{x} = 8$

Step 3

Create expressions in the equation that all have equal bases.

${(2^{- 1})}^{x} = 2^{3}$

Step 4

Rewrite ${(2^{- 1})}^{x}$ as $2^{- x}$ .

$2^{- x} = 2^{3}$

Step 5

Since the bases are the same, then two expressions are only equal if the exponents are also equal.

$- x = 3$

Step 6

Solve for $x$ .

$x = - 3$

Step 7

The variable $x$ is equal to $- 3$ .

$- 3$