How the first statement is sufficient?
In the xy-plane, at what two points does the graph of y = (x+a)(x+b) intersect the x-axis?
1) a+b = -1
2) The graph intersects the y-axis at (0,-6)
Ans is C ?
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
DS problem - graph
This topic has expert replies
-
jayhawk2001
- Community Manager
- Posts: 789
- Joined: Sun Jan 28, 2007 3:51 pm
- Location: Silicon valley, California
- Thanked: 30 times
- Followed by:1 members
1 - insufficient. All we have it x^2 -x + ab = 0. Cannot
solve for x
2 - insufficient. y = x^2 + (a+b)x + ab implies ab = -6. Cannot
solve for x
Using 1 and 2
x^2 - x - 6 = 0
x = 3 & -2
So, C looks like the correct answer
solve for x
2 - insufficient. y = x^2 + (a+b)x + ab implies ab = -6. Cannot
solve for x
Using 1 and 2
x^2 - x - 6 = 0
x = 3 & -2
So, C looks like the correct answer
