MathRevolution wrote:
[GMAT math practice question]
In the coordinate plane, is the x-intercept of the line ax + by + c = 0 less than 0?
1) ac > 0
2) bc > 0
To find x-intercept, put y = 0 in the given equation
--> ax + b(0) = c
--> x = c/a
x-intercept (c/a) is <0 when
Case 1: a<0 & c>0
Case 2: a>0 & c<0
1) ac > 0
--> Both a & c are of same sign
--> x-intercept is always >0[A Definite NO]
Sufficient
2) bc > 0
Does not talk about 'a'
Insufficient
IMO Option A
Pls Hit Kudos if you like the solution
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