Expert: Josh - 2/4/2010

Question
Write the equation in standard form using integers
y = 4x -11
how do I do this?

Answer
The standard form for a straight line equation is generally acknowledged as Ax + By = C, where A > 0.

Example: x+2y=3 and 4x+8y=12 both describe the same line. So which one do we choose?
Given numerous choices that are possible, we generally select the coefficients A, B, and C so that they are relatively prime integers. i.e., ensuring that they do not share a common factor. So, we would prefer x+2y=3 over 2x+4y=8 or 4x+8y=12, even though they are essentially the same.

Your task in this question is to simply rearrange y=4x-11 (in gradient-intercept form) to the standard form (i.e., an equation that resembles Ax+By+C=0). So, you need to determine the coefficients A, B and C, given the equation y=4x-11.

Subtracting y from both sides (left and right) of the equation, we get
0=4x-y-11. This, already is in standard form.

If you define standard form as Ax+By=C, then A=4, B=-1, C=11.
Alternately, if you use Ax+By+C=0, then A=4, B=-1, C=-11.