Question

Describe the mathematic process of canceling like factors when working with rational expressions. Demonstrate this with an example.

Answer 1

x² + 8x + 15 (x + 3)(x + 5)
----------- = --------------
x² - x - 12 (x + 3)(x - 4)

By factorising both numerator and denominator we find that (x + 3) is a common factor,
so we cancel it and are left with

x + 5
-----
x - 4

Answer 2

thank you

Answer 3

can you explain the process in words for rational expressions>

Answer 4

I got it! :) thanks though

Answer 5

do i need to explain anything now???

Answer 6

for this example you should know how to find factors of a quadratic expression...

Answer 7

to help you, i searched and found the following site...
it gives steps how to factorise a quadratic polynomial....

http://www.teacherschoice.com.au/sample_help_1_alg.htm

Answer 8

thank you, no I understand. thanks you

Answer 9

u cud also have case like...

2x + 10
-------
x² - 25

here numerator can be rearranged to 2(x + 5)
denominator can be rearranged as (x)² - (5)² = (x + 5) (x - 5)

so
2x + 10 2(x + 5)
------- = ------------
x² - 25 (x + 5)(x - 5)

so cancelling out the common factor (x + 5), we get
2
------
x - 5