Posted by Alison on Saturday, January 22, 2011 at 7:15pm.
Given Equation AX + BY + C = 0, which following conditions would be true for graph of line to have a negative slope and a postive yintercept?
A. A>0, B>0, C>0
B. A>0, B<0, C>0
C. A>0, B>0, C<0
D. A>0, B<0, C<0
I cant figure this out!

MATH EMERGENCY  helper, Saturday, January 22, 2011 at 7:28pm
In this form
Ax + By + C = 0
Slope m = A/B
yintercept b = C/B
You are looking for, a negative slope
Slope m = A/B
And, a positive yintercept
C/B
So,
Ax + By  C = 0
Can you answer now? 
MATH EMERGENCY  Alison, Saturday, January 22, 2011 at 8:02pm
I still don't get it:\
Is C the yintercept? or B?
How do I know which one is greater or less? This is mind twisting, i don't get it 
MATH EMERGENCY  bobpursley, Saturday, January 22, 2011 at 8:05pm
I would change it to slope intercept form
y=mx+b
ya/b x c/b
so for a negative coefficent of x, both a,b have to be positive, or both have to be negative. A positive y intercept means that c or b has to be negative, but not both. 
MATH EMERGENCY  Alison, Saturday, January 22, 2011 at 8:08pm
Ok. That kind of makes sense.

MATH EMERGENCY  Henry, Sunday, January 23, 2011 at 3:02pm
To have a negative slope and positive
yint, A and B must have the same sign
, C must have the opposite sign.
Therefore, the answer is C.
If the Eq was in this form:
AX + BY = C; A, B, and C must have the
same sign.