Question: I'm noob in Mathematics. Currently I'm experiencing with **Exponent** Equation. I know exponent can be added if we multiply and subtract if we divided. But I'm lost how the following first equation sorts out to the second one.

$$a = \frac{e^3}{e^3 + e^2}$$
$$a = \frac{1}{1 + e^{2-3}}$$

**e** is the **Euler's number** (base of the natural logarithm). But the equation works with any base number.

Answer: 
Use
$$ \frac x{y+z}=\frac x{x\cdot(\frac yx+\frac zx)}=\frac1{\frac yx+\frac zx}.$$
$a = \frac{e^3}{e^3 + e^2}$ -- (1)

Factor out $e^{3}$ from the denominator in (1). That is, 
$a$
$= \frac{e^3}{e^{3}(e^{3 - 3} + e^{2 - 3})}$
$= \frac{e^3}{e^{3}(e^{0} + e^{- 1})}$ -- (2) 

From (2), we conclude via this rule: $x^{0} = 1$ where $x ≠ 0$ that 
$$a = \frac{1}{1 + e^{- 1}}$$