SOLUTION: the graph of ax+by=5 in the xy-plane contains points from each of quadrants I,II and III, but no points from Quadrant IV. Which of the following must be true? A) a>0 and b>0 B) a

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: the graph of ax+by=5 in the xy-plane contains points from each of quadrants I,II and III, but no points from Quadrant IV. Which of the following must be true? A) a>0 and b>0 B) a      Log On


   

Question 1040773: the graph of ax+by=5 in the xy-plane contains points from each of quadrants I,II and III, but no points from Quadrant IV. Which of the following must be true?
A) a>0 and b>0
B) a>0 and b<0
C) a<0 and b>0
D) a<0 and b<0
Found 2 solutions by Boreal, solver91311:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
No points in Quadrant IV means a>0 and b is <0.
B is the answer.
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Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


If the graph does not traverse any portion of QIV, then both the slope and the y-intercept must be positive. Putting the equation into slope intercept form:



So



and




John

My calculator said it, I believe it, that settles it