Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2015-05-07 03:49:26

Kaylee522
Guest

Quadratic Equations with Complex Numbers

Ok so here's the thing, I've tried this problem a lot of times and other people have tried and we just can't seem to get the same answers as the multiple choice answers. If you can walk me through the steps of this maybe I can find a solution. I'm copying this right off the website by the way. 

1. -4 1/5x^2 + 1 2/5x - 2 4/5 = 0

A. x = {1 +- i[SQRT(23)]}/6
B. x = {-1 +- i[SQRT(10)]} / 6
C. x = {1 +- [SQRT(23)]} /-6
D. x = 1 +- 5/2 x^2
E. x = -1 +- 2/5 x^2
F. x = 2 +- 20 x^2

#2 2015-05-07 05:44:01

Bob
Administrator
Registered: 2010-06-20
Posts: 10,052

Re: Quadratic Equations with Complex Numbers

hi Kaylee522

Welcome to the forum.

If that is exactly how the question was presented, then I'm not surprised many different answers have been obtained.  Is this from  CompuHigh by any chance?

Here's a few possible interpretations of that first term alone:

The other terms similarly.  I think the questioner meant:

As I can get one of the offered answers with this I'll show you how to get started:

Multiply be 5.

Now divide by 7

Can you finish it from here?

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

Offline

Board footer

Powered by FluxBB