Algebra Examples

$\frac{7 (2^{x}) - 8 \cdot 2^{x - 2}}{2^{x + 1} - 2^{x - 1}}$

Step 1

Factor out negative.

$\frac{7 \cdot 2^{x} - (8 \cdot 2^{x - 2})}{2^{x + 1} - 2^{x - 1}}$

Step 2

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

$\frac{7 \cdot 2^{x} - (2^{3} \cdot 2^{x - 2})}{2^{x + 1} - 2^{x - 1}}$

Step 3

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

$\frac{7 \cdot 2^{x} - 2^{3 + x - 2}}{2^{x + 1} - 2^{x - 1}}$

Step 4

Subtract $2$ from $3$ .

$\frac{7 \cdot 2^{x} - 2^{x + 1}}{2^{x + 1} - 2^{x - 1}}$