OT: Any Math people in here?

  • Sponsors (?)


Sorry, it's been too long ago. This kind of math is not used in my simple life. I just need to add and subtract to balance my checkbook. :D

My son could probably do it, a chemist by major, but he's too busy saving the world, one video game at a time. Good luck.
 
Peaked my interest then realized I'm too old. I'd just math it out and not reduce. I do remember taking out the numbers if divisible.

2a(sq)m-8b(sq)m/ax+2bx

then you can remove like symbols but I don't remember how they have to coincide. I think they have to be through the whole equation like the numbers but maybe not.

I'm going back to my wheels. I know what a 100lbs of torque is.

Ooh--[2a(sq)-8b(sq)]m/[a+2b]x There is your answer...I think
 
I hope to teach this crap to kids someday so I figured I give this problem a try.

I think all we want to do is pull out common factors and reduce the fraction so the terms in the top part...

8*a^2*m - 32*b^2*m

have 8 and m in common. We can pull those out to rewrite it as...

(a^2 - 4*b^2)*(8*m)

The terms have nothing else in common so that's it for the top. Now for the bottom...

4*a*x + 8*b*x

Okay so in the bottom part we can see that the terms have 4 and x in common (4 and x are multiplied with both a and 2*b) so let's pull those out.

(a + 2*b)*(4*x)

So our fraction (it's not an equation because they haven't given us an = sign) becomes...

(a^2 - 4*b^2)*(8*m)
---------------------
(a + 2*b)*(4*x)

This is where the crappy part comes in. If you look at the terms on top and on bottom there is something they have in common (we can divide things into other things). It's real easy to see that we can divide 8 by 4 to get...


(a^2 - 4*b^2)*(2*m)
---------------------
(a + 2*b)*x

But we can also do something with (a + 2*b). It will divide into (a^2 - 4*b^2) if we factor (rewrite) the top into (a + 2*b)*(a-2*b). If you use "foil" on it you'll see that...

(a + 2*b)*(a - 2*b) becomes a^2 + 2*a*b - 2*a*b - 4*b^2 which is a^2 - 4*b^2

That's the crappy part, not so much the foil thing, but seeing that (a^2 - 4*b^2) can be factored.

Okay so now if we factor and rewrite our fraction we see...

[(a + 2*b)*(a - 2*b)]*(2*m)
----------------------------
(a + 2*b)*x

So you can see that the (a + 2*b) can divide into the top, I like to say that it cancels out since it is on both top and bottom. and our fraction becomes...

(a - 2*b)*(2*m)
----------------
x

Smooth huh? No it sucks I'm not going to lie to you, but it's math and it is an important tool that can be used to solve a lot of problems (like figuring out how far you can go on a tank of gas, or your suspension geometry). Learn it and you be ahead of so many others that can't do it. A TI 89 will solve these type problems symbolically. It is an awesome tool that really helps with the algebra crap. Don't go to engineering school without it.

That help?
 
i don't unserstand how you guys can understand that crap at all. i failed algebra every time i took it, even in college. had to take the "comsumer" math courses in place of them. the only algebraic equation i was ever to able to use and make it work was for figuring out the acoustics of a given room (sound tech major) math was the one subject in school that i absolutely hated, well just algebra really. most stuff i can figure in my head but this crap puts my brain in a coma!!!!! maybe that's why i spend most of my time on online forums now. LOL. seriously, the better you can get at this stuff the better off you'll be in life later down the road.
 
i guess its just reg. algebra. Im taking an online school through my work so I can get a better job...I wont use any of this stuff in the job i want because we have computer programs for the job that does everything..the course is for an ass.in electrical engineering tech.
 
Here are the solutions for the third and forth problem.
math%20prob1.jpg

I hope you can read this.
math%20prob2fix.jpg


Good luck with it. Man it looks like he's a hard #$$ from these problems. I always hated it when my teachers would take a simple concept and twist it up with a bunch of others and then call that a fair test of your knowledge.
 
blue65coupe said:
Maybe it's been too long but you can't independently break down the top and bottom can you? That changes the whole fraction. Top and bottom have to have same properties to cancel out


I'm out...been too long

Yes you can. It's alright as long as you don't take anything away from the top.

8/7 can be rewritten as (3 + 5)/7, or (5 + 3)/7