Post a New Question

MATH EMERGENCY

posted by on .

Given Equation AX + BY + C = 0, which following conditions would be true for graph of line to have a negative slope and a postive y-intercept?

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 - ,

    In this form
    Ax + By + C = 0

    Slope m = -A/B
    y-intercept b = -C/B


    You are looking for, a negative slope
    Slope m = -A/B

    And, a positive y-intercept
    C/B

    So,
    Ax + By - C = 0

    Can you answer now?

  • MATH EMERGENCY - ,

    I still don't get it:\

    Is C the y-intercept? or B?

    How do I know which one is greater or less? This is mind twisting, i don't get it

  • MATH EMERGENCY - ,

    I would change it to slope intercept form
    y=mx+b

    y-a/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 - ,

    Ok. That kind of makes sense.

  • MATH EMERGENCY - ,

    To have a negative slope and positive
    y-int, 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.

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question