# Is there a mistake in this solution?

## Homework Statement

I'm given an equation Ax + By + C = 0
The answer in the back says:

If B not= 0, the set is the graph of f(x) = (-A/B)x + (-C/A)

How can the last term be (-C/A)??

Shouldn't it be C/B ?

## The Attempt at a Solution

y = (-Ax - C)/B
y = (-A/B)x - (C/B)

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rock.freak667
Homework Helper
Yes it should be C/B. Perhaps it is a typo?

Looks like there's probably an error in the back of the book (or in the front where the problem statement is, depending on how you look at it). You math looks good to me.

yes, you are right, -C/B is correct.

I dont know why but math text book has lots of errors like this.

HallsofIvy
Homework Helper
I am greatly confused! You ask "How can the last term be (-C/A)?? Shouldn't it be C/B ?"
but then everyone agrees withy you that it should be -C/A???

What am I missing?

I think you are missing this part

"3. The Attempt at a Solution

y = (-Ax - C)/B
y = (-A/B)x - (C/B) "

so zeion's attempt is right

Last edited:
HallsofIvy
Homework Helper
Yes, I saw that. His answer was correct and exactly the same as
"The answer in the back says:
If B not= 0, the set is the graph of f(x) = (-A/B)x + (-C/A)"

"How can the last term be (-C/A)??
Shouldn't it be C/B ?"

And why has no one attempted to answer that question (if you understood it)?

eumyang
Homework Helper
I am greatly confused! You ask "How can the last term be (-C/A)?? Shouldn't it be C/B ?"
but then everyone agrees withy you that it should be -C/A???

What am I missing?
Instead of the bolded, do you mean -C/B? Are you bringing to our attention the negative? Should zeion have said this?

If B not= 0, the set is the graph of f(x) = (-A/B)x + (-C/A)

How can the last term be (-C/A)??

Shouldn't it be (-C/B)?

P.S. What I'm confused about is that I remembered that there were a lot more posts in this thread than there currently are. Were some of them deleted?