How would you write 0.3y + 1.2 = –0.4x in standard form?

Question

whpalmer4 · Answer

Standard form is Ax + By = C, with A and B not zero.  Rearrange your equation so x and y are on one side and any leftover numbers are on the other.

anonymous · Answer

0.4x+0.3y=-1.2?

whpalmer4 · Answer

Yes, I believe that is correct.

anonymous · Answer

Thank you

whpalmer4 · Answer

Standard form is handy if you want to quickly graph the line.  at x = 0 (y-intercept), A(0) + By = C, so the y-intercept is just C/B.  Similarly, for the x-intercept (y = 0) Ax = C, so the x-intercept is just C/A.  Plot (0,C/B) and (C/A,0), draw a straight line through them, and you are done!

For example:
$$y = x + 2$$$$-1x + 1y = 2$$
A = -1, B = 1, C = 2
Plot points (0,2) and (-2,0), draw line through them: