polynomial long division: (3x^2 + 10x - 9) / (3x - 2)

[santasad13]

I have a lot of these long-division problems, and am having a lot of trouble figuring them out. Here's an example:

(3x^2 + 10x - 9) / (3x - 2)

 

[arthur ohlsten]

do it just like 3109/3

3x-2 divided into 3x^2+10x-9
3x goes into 3x^2 , x times
x times [3x-2]=3x^2-2x
subtract this from the numerator and get
12x-9
3x goes into this 4 times, multiply the divisor by this and you get
12x-8
subtract this and we get -1

the answer is x+4 with remainder -1

 

[santasad13]

oh, thanks. that makes sense

 

[arthur ohlsten]

Glad it made sense; math usually does.

When you divide polynomials, if the numerator is "missing" terms, place the missing term with a coefficient of 0. Example:

2x^4+ 3x^2 +7

becomes

2x^4+0x^3+3x^2+0x+7

When you do the long division, you will see why.

arthur