Evaluate 2^-3*4^-9

$2^{- 3} \cdot 4^{- 9}$

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{1}{2^{3}} \cdot 4^{- 9}$

Raise $2$ to the power of $3$ .

$\frac{1}{8} \cdot 4^{- 9}$

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{1}{8} \cdot \frac{1}{4^{9}}$

Combine fractions.

Combine.

$\frac{1 \cdot 1}{8 \cdot 4^{9}}$

Multiply $1$ by $1$ .

$\frac{1}{8 \cdot 4^{9}}$

Simplify the denominator.

Rewrite $8$ as $2^{3}$ .

$\frac{1}{2^{3} \cdot 4^{9}}$

Rewrite $4$ as $2^{2}$ .

$\frac{1}{2^{3} \cdot {(2^{2})}^{9}}$

Multiply the exponents in ${(2^{2})}^{9}$ .

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\frac{1}{2^{3} \cdot 2^{2 \cdot 9}}$

Multiply $2$ by $9$ .

$\frac{1}{2^{3} \cdot 2^{18}}$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$\frac{1}{2^{3 + 18}}$

Add $3$ and $18$ .

$\frac{1}{2^{21}}$

Raise $2$ to the power of $21$ .

$\frac{1}{2097152}$

The result can be shown in multiple forms.

Exact Form:

$\frac{1}{2097152}$

Decimal Form:

$4.76837158 \cdot 10^{- 7}$