Question

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

Answer 1

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.

Answer 2

0.4x+0.3y=-1.2?

Answer 3

Yes, I believe that is correct.

Answer 4

Thank you

Answer 5

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: