Factoring Quadratics... How? (NancyPi)

MIT grad shows how to factor quadratic expressions. If you want to skip to the shortcut method, jump to 5:06. Nancy formerly of MathBFF explains the steps.

The shortcut method ("The Magic X") helps you factor any tough quadratic that doesn't begin with x^2 but instead begins with 2x^2 or 3x^2, or 4x^2, etc.

1) IF YOUR QUADRATIC STARTS WITH X^2: It is faster to use the normal method for factoring in this case: trial and error. Say you have x^2 + 4x - 12. You need to find two numbers that multiply to the last number, -12, AND that add to the second coefficient, positive 4. First make a list of all pairs of numbers that multiply to -12. Then check which pair also adds to positive 4. Use the two numbers in this pair to write your factors.

2) IF YOUR QUADRATIC STARTS WITH 2X^2 OR 3X^2 OR 4X^2, ETC:
A) First check whether your leading coefficient (2 or 3 or 4, etc) is just an overall constant that you can factor out of every term in the quadratic. If it is, factor it out first and then use Method #1 above to factor the X^2 expression that remains.
B) If your leading coefficient cannot be factored out evenly from every term, it will be faster and easier to use the shortcut "magic X" method instead of Method #1. See this method explained at time 5:06 in this video.

[silverr-is-me]

I know you're never going to see this but you have saved my life

[tawwy]

your voice is the most calming thing when you’re having a breakdown, thank you so much

[martinbilis]

When my teachers started doing this it was all too complicated too quickly, pretty sure that your explanation saved my life, thanks so much.

[noorzilla]

Everyone: *watches and tries to understand

Me: tries to figure out how she's writing🤔

[TheViViDiMaGeS]

“you don’t have to like math, but you can like my video” we love you. i thought i was about to have to cheat my way through the end of my math class and you saved me. thank you for being so much better than my actual math teacher<3

[lynnebalzer]

I like your relaxed, laid back style. It gives me hope that I can master this without struggling all the time.

[Jonathan-vxxi]

My teacher literally wants us to go by trial and error. I said "there must be a better way!" and looked you up immediately. You are a godsend, magic x trick for the win. Little does she know, I got NancyPi in my corner. Thank you thank you thank you!!!

[bazookahoops]

You taught me more in 10 minutes than my teacher did in 3 class days

[Emjay_Music]

I was this close to just dropping out. I am not great at algebra and I feel like I’m just burned out and done. Your video helped soothe that frustration I’ve been on YouTube for an hour sifting through a dozen long confusing videos. I appreciate that you have posted this thank you so much. Your voice is soothing which helped with my frustration and the explanation was clear and simple. Again THANK YOU.

[paintwithshane]

anyone else cramming this in before a test

[Hello-uumm]

My teacher was literally using squares and triangles to factor and I wanted to kms thanks for helping Nancy ❤️

[nmadero]

This is truly amazing, I spent all of high school dreading this but she makes this really understandable. Very grateful, thank you!!

[Ayumi-kmxi]

I LOVE YOU NANCY. i was near tears minutes ago because nothing my teacher said made any sense. If only all teachers were as helpful as you ;-;

[samirahman]

Why would someone dislike this. I mean... you guys get how many students she saved from failing? Including me LOL

[Storiesofsam_]

Is she writing backwards? What?! Genius. If this is hard for me staring at the paper in the usual order, I couldn’t imagine writing everything facing the other way

[endofcorporategiants]

I loved this explanation, math seriously has widen since I was in school, my brother needed help and this video pretty much just taught us how to simplify something so difficult, you are my Go-to match teacher from now on

[marjoriejohnson]

So, Im 37, and have been out of math class for a long time...in fact I'm convinced I got a B in college algebra bc I ran into my professor at a bar one night, but anyway. I've been trying to just see how much I could remember and I literally put my book away already and did some dishes because for some reason, quadratics are always my kryptonite. Thank you SO MUCH for this video. I just got 5 correct in a row and feel like a friggin' magician.

[davidrusso]

Basic Type Factoring: 0:32
Factor out a GCF, Then Revert Back to Basic Type Factoring: 3:48
Magic-X Technique: 5:09

[f.spopers]

You literally taught me more in 9 minutes than I ever learned in 2 weeks from my geometry class trying to figure this out

[geralynpinto]

Unlike most of those who watch your videos, I am not a student of maths but a college lecturer in English who pursues maths as a hobby. And you have strengthened my interest and determination to work on the subject. I want to congratulate you on your systematic approach and clarity which make your lessons invaluable. Many thanks.