If I have:

$\displaystyle y = \frac{e^3x + 4}{e^2x}$

Can I simply as you would eg with x^3/x^2?

Can I call it:

$\displaystyle y = e^x + \frac{4}{e^2x}$

What are the rules in simplifying these? Or can you not?

Angus

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- Dec 30th 2011, 04:29 AMangypangyCan I simply e^3x/e^2x ?
If I have:

$\displaystyle y = \frac{e^3x + 4}{e^2x}$

Can I simply as you would eg with x^3/x^2?

Can I call it:

$\displaystyle y = e^x + \frac{4}{e^2x}$

What are the rules in simplifying these? Or can you not?

Angus - Dec 30th 2011, 05:32 AMearbothRe: Can I simply e^3x/e^2x ?
1. I assume that you mean $\displaystyle y = \frac{e^{3x} + 4}{e^{2x}}$

2. Re-write the RHS as a product

$\displaystyle y = \frac{e^{3x} + 4}{e^{2x}}=\left( e^{3x} + 4 \right) \cdot \frac1{e^{2x}}$

3. Expand the RHS and cancel equal factors:

$\displaystyle \left( e^{3x} + 4 \right) \cdot \frac1{e^{2x}} = \frac{e^{3x}}{e^{2x}} + \frac4{e^{2x}}$ - Dec 30th 2011, 05:54 AMHallsofIvyRe: Can I simply e^3x/e^2x ?
Or write it as: $\displaystyle \left(e^{3x}+ 4\right)e^{-2x}= e^{3x- 2x}+ 4e^{-2x}= e^{x}+ 4e^{-2x}$.

- Dec 30th 2011, 06:29 AMangypangyRe: Can I simply e^3x/e^2x ?