Standard form question
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# Standard form question

[From: ] [author: ] [Date: 11-07-05] [Hit: ]
theres not much of an advantage with one form versus the other.3)(y - 15) = 4(x - 3)(point-slope...I arbitrarily chose (3,The last form is a little rare.......
So I know that it is Ax + By = C
Say I have -3x + y = 3
Is it acceptable to write it as 3x - y = -3?
Or is that just plain wrong?

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Actually in standard form, A should be positive.

So 3x-y=-3 is better!

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Here's the thing about standard form...there IS no standard way to write it! Algebra textbooks vary.

Some say Ax + By = C is standard form.
Some say Ax + By + C = 0 is standard form.
Some state A must be >= 0.
Some just say that at least one of A or B must be positive. (If it's a double negative coefficient, multiply both sides by -1.)

Frankly, it doesn't matter which form your book uses...there's not much of an advantage with one form versus the other.

The REAL key is that you're able to convert from these four equations:
1) y = 4x + 3 (slope-intercept)
2) 4x - y = -3 ("standard form")
2A) 4x - y + 3 = 0 (alternate "standard form")
3) (y - 15) = 4(x - 3) (point-slope...I arbitrarily chose (3,15) since it's on the graph)
3A) y = 4(x-3) + 15 (some books write point-slope in this form)
4) (y - 15) = [(15-11) / (3-2)] * (x-3)

The last form is a little rare. It's a double-point form where the slope between (2,11) and (3,15) isn't simplified. Most of the time, you'll just wind up calculating the slope first anyway, so you'll get (15-11)/(3-2) = 4/1 = 4, so it's really the same as equation #3.

If you can see that all of those equations are the same, and you can quickly see that the slope is 4, the y-intercept is 3, and that the points (0,3), (2,11), and (3,15) all live on the line, you'll do well.

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-3x + y = 3
y = 3x + 3

3x - y = -3
-y = -3x - 3
y = 3x + 3

yes it is acceptable, dw;)

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This is a linear equation so standard form should be written as y=mx+b. It should be written as y=3x+3.
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keywords: form,Standard,question,Standard form question
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