# Thread: Help with changing subjects!

1. ## Help with changing subjects!

im having trouble in changing subjects for equations, such as
4n-3nsquared= -1.. is there like a simple formula for changing the numbers around so it makes sense as in axsquared+bx+c=0?
I usually just do simple math to figure where each number goes like for 4n-3nsquared= -1, i usually think about 4-5=1 and rearrange it to make the equation make sense in the form of axsquared+bx+c=0...
This is for quadratics, so if the question is in the form of axsquared+bx+c=0, then its very easy to solve.

2. Originally Posted by xanith_47
im having trouble in changing subjects for equations, such as
4n-3nsquared= -1.. is there like a simple formula for changing the numbers around so it makes sense as in axsquared+bx+c=0?
I usually just do simple math to figure where each number goes like for 4n-3nsquared= -1, i usually think about 4-5=1 and rearrange it to make the equation make sense in the form of axsquared+bx+c=0...
This is for quadratics, so if the question is in the form of axsquared+bx+c=0, then its very easy to solve.

If you mean,
$4n-3n^2=-1$
Multiptly by -1 but sides to get,
$3n^2-4n=1$
Subtract 1 thus,
$3n^2-4n-1=$
Thus,
$\left\{ \begin{array}{c}{a=3\\b=-4\\c=-1\end{array}\right$