2.32 x2 - 15.5 x =81.03


what are the 2 values for X?

does anyone know hwo to do this one

1/18/2006 2:41:49 AM

A quadratic equation has solutions given by the quadratic formula, see below.

ax^2+bx^2+c=0 has solutions x = [-b plus/minus Sqrt(b^2 - 4ac)]/2a

you can derive this by completing the square, but I guess you probably just need to notice

a=2.32
b=-15.5
c=-81.03

(your equation is same as 2.32 x2 - 15.5 x -81.03 = 0)

1/18/2006 2:46:24 AM

you could graph it on your graphing calculator and see where it crosses the X axis. those are the solutions.
~skip

1/18/2006 8:25:47 AM

This is a joke, right?

1/18/2006 10:10:47 AM

^ I hope so. I learned to do this in like 8th grade.

1/18/2006 10:13:05 AM

probably not a joke. but i can see someone not remembering to use the quadratic formula if they haven't used it since they learned it in the 8th grade. i bet once he saw mathman's explanation it clicked in

1/18/2006 10:26:00 AM

Let's hope so

1/18/2006 5:17:46 PM

I love how people admit they couldn't solve a quadratic equation until the 8th grade and then are condescending to others.

1/19/2006 11:32:59 AM

^are you kidding? This is like...5-8 fucking years after 8th grade, but i'm sure you knew the shit in kindergarten because that's the only fucking way this would be the same

1/19/2006 11:41:19 AM

I'm not saying it's the same. I would expect any college student to solve the quadratic equation. Still that comment sounds kind of like:

What? You can't read? What a dumbshit! If you wanna know, by the age of 15 I already knew like half the alphabet. Eat that, motherfucker!

1/19/2006 11:45:54 AM

not really. what kind of arbitrary education system are you comparing this to?

kids read by 5, a decade earlier than your example, so are you saying you should be learning algebra at age 3? I really want to see this curriculum.


[Edited on January 19, 2006 at 11:51 AM. Reason : I know this shit is relative, but still. It's what was taught at that age...]

1/19/2006 11:50:08 AM

Algebra II - 11th grade for me

1/19/2006 12:32:51 PM

I was in a 10 grade school. I don't remember what we did in the 8th grade, but in the 9th we differentiated. Does it answer your question?

1/19/2006 1:28:18 PM

im usually rude, but you people take the cake

1/19/2006 2:27:45 PM

Most of us went to 12-grade schools. I had algebras around grades 8-10, and calculus in grade 12. And I was advanced compared to most. (Of course, I was in a pretty crappy school system.)

1/19/2006 3:00:12 PM