SOLUTION: Would someone please clarify my math on this? The quadratic equation came out to: 4+/- 2 times radical 10, all divided by 4. To solve, I divided each term in the numerator by

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: Would someone please clarify my math on this? The quadratic equation came out to: 4+/- 2 times radical 10, all divided by 4. To solve, I divided each term in the numerator by      Log On


   

Question 979810: Would someone please clarify my math on this?
The quadratic equation came out to: 4+/- 2 times radical 10, all divided by 4.
To solve, I divided each term in the numerator by 4, yielding 1 +/- radical 10 divided by 2.
However, the solution factored the 4 in the numerator and denominator, then canceled out three 2s to yield 2 +/- radical 10, all divided by 2.
They both calculate out to the same thing. But, so that I don't make future mistakes, it seems that either the solution didn't go all the way, or I did something that may have worked here, but is in fact wrong and may not work in the future.
Thanks for your thoughts.
Helen

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
4+/- 2 times radical 10, all divided by 4.
%284+%2B-+2sqrt%2810%29%29%2F4

You can either do as you did and make two fractions:

4%2F4+%2B-+2sqrt%2810%29%2F4

The simplify as

1+%2B-+sqrt%2810%2F2%29

Or else you can factor 2 out of the numerator:

%282%282+%2B-+sqrt%2810%29%29%29%2F4

Then divide numerator and denominator by 2

%282+%2B-+sqrt%2810%29%29%2F2

They are both correct and equal.

It's very similar to the question of whether we 
prefer 3%2F2 to 1%261%2F2.  Your teacher could not 
mark either one wrong.

Edwin