# Need help with this equation transformation

• February 16th 2013, 09:42 AM
Assassinbeast
Need help with this equation transformation
Hey man :)

I have starred on this equation extremely long time, and i just cant get it why this is true (or how it is done) :

I really hope someone could help me and show a complete step by step on how its done.
Thanks alot :-)
• February 16th 2013, 09:46 AM
ILikeSerena
Re: Need help with this equation transformation
Hi Assassinbeast! :)

A fraction remains the same if you multiply numerator and denominator both by the same number.

And when you want to add fraction, you first have to make the denominators the same, and then you can add the numerators.

$\frac{b^2}{4a} - \frac{b^2}{2a} + c$
$= \frac{b^2}{4a} - \frac{b^2 \cdot 2}{2a \cdot 2} + c \cdot \frac {4a}{4a}$
$= \frac{b^2}{4a} - \frac{2 b^2}{4a} + \frac {4ac}{4a}$
$= \frac{b^2 - 2 b^2 + 4ac}{4a}$