# Find the sum or difference in the lowest term?

• February 21st 2009, 06:38 AM
mj.alawami
Find the sum or difference in the lowest term?
1) $\frac{a+1}{a^3} - \frac{a+2}{a^2} +\frac{a+3}{a}$

Attempt:
$\frac{a^4-a^3+2a^5+a^6}{a^6}$

Thank you for your help and for taking the time to read my question (Happy)
• February 21st 2009, 06:45 AM
skeeter
Quote:

Originally Posted by mj.alawami
1) $\frac{a+1}{a^3} - \frac{a+2}{a^2} +\frac{a+3}{a}$

Attempt:
$\frac{a^4-a^3+2a^5+a^6}{a^6}$

Thank you for your help and for taking the time to read my question (Happy)

$a^3$ is the LCD ...

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

$\frac{a+1}{a^3} - \frac{a(a+2)}{a^3} +\frac{a^2(a+3)}{a^3}$

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

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

$\frac{a^3+2a^2-a+1}{a^3}$
• February 21st 2009, 06:47 AM
http://www.mathhelpforum.com/math-he...8674cee3-1.gif

Just a little more

$= \frac{a^3(a -1+2a^2 + a^3 )}{a^3 \times a^3}$

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

(Nod)
• February 21st 2009, 07:01 AM
mj.alawami
Quote:

Originally Posted by skeeter
$a^3$ is the LCD ...

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

$\frac{a+1}{a^3} - \frac{a(a+2)}{a^3} +\frac{a^2(a+3)}{a^3}$

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

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

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

Thanks aloots (Clapping)