Help Algebra Argh

meathite

Can someone please help this question has been doing my head in all weekend, i just don't understand it.

(1) Find the product of three linear factors by expansions and then do three successive examples of polynomial division. (ie. devide your cubic equation by each of the linear factors in turn)

Help would be appreciated

meathite

I'm just looking to how i might start it the question is confusing me so

MathsManiac

This question is obviously for practising multiplying and dividing in algebra.

If what you were being asked to do was in arithmetic, it would be: pick any three prime numbers. Multiply them together and see what you get. Then divide the answer by each of the three numbers in turn. (You would expect them each to divide in evenly.)

e.g. 3*5*11 = 165.
165/3 = 55
165/5 = 33
165/11 = 15.

Now try it in algebra. A "linear factor" just has x's and numbers, like (x+2) or (2x-1).

Pick any three linear factors (e.g. (x+2), (2x-1) and (x+3)). Then multiply them together. That is, multiply two of them out and then multiply the answer by the third one.

This will give you a cubic expression - it will have an x^3 term, an x^2 term, an x term and a number.

Then divide that cubic expression by each of the three linear factors in turn.

If you've done everything right, then you should get no remainder each time you divide.

Does that help?

meathite

i think so i'm going to try ok oh and thanks Mathsmanic if i get stuck later will you help me

MathsManiac

Subject to being around. (I don't actually live on line!)