What would be the quickest way to multiply this polynomial? (x-3)(x+2)(x^2+3x-5)
Wolframalpha showed me this method but I do not know what it is called and how it works?
Wolframalpha showed me this method but I do not know what it is called and how it works?
1 Answer
Below
Explanation:
The method that Wolfram alpha showed you isn't something that teachers would recommend. However, it is still pretty useful! I haven't seen it in a long time so I don't remember what this is called.
Basically what you would do is to multiply normally but instead you have some x's in your equation as well.
Your first row is:
Your second row is:
Your third row is:
Now all you have to do is line your rows up ie
#-5x^2+5x+30#
#3x^3-3x^2-18x#
#x^4-x^3-6x^2#
Once you've lined it all up, you can just add them together and you'll get your answer.
OR
you could honestly just add them all up like this: