On 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 y-intercept is (0,-6)
I know the x-int. will be points (?,0) but I don't know how to find the x-point.
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At what two points does this line cross the x-axis?
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Bens4vcobra
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Hi,
This question has been discussed a lot of times. There are at least 10 threads. Please use the BTG search engine before posting questions. That will save you a lot of time. Here is one of the threads:
https://www.beatthegmat.com/coordinate-g ... 73005.html
This question has been discussed a lot of times. There are at least 10 threads. Please use the BTG search engine before posting questions. That will save you a lot of time. Here is one of the threads:
https://www.beatthegmat.com/coordinate-g ... 73005.html
Cheers!
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amit2k9
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equation is y= x^2 + (a+b)x +ab hence values of (a+b) and ab have to be known.
a+b gives the same. C it is.
a+b gives the same. C it is.
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SUHAILK
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this is equation of parabola intersecting x axis at points x = -a & x = -b
so we have to solve for x
(x+a)*(x+b) = 0
x^2+(a+b)x+ a*b = 0 ................(1)
we have following info in hand:
1) a+b = -1
2) ab = -6
substitute this in eq (1)
we get
x^2-x-6 = 0
=> x = 3,-2
so we have to solve for x
(x+a)*(x+b) = 0
x^2+(a+b)x+ a*b = 0 ................(1)
we have following info in hand:
1) a+b = -1
2) ab = -6
substitute this in eq (1)
we get
x^2-x-6 = 0
=> x = 3,-2
