2x² - 5x - 3 = 0
2x² - 6x + 1x - 3 = 0
2x(x - 3) + 1(x - 3)
(2x + 1)(x - 3)
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Roots
2x + 1 = 0
2x + 1 - 1 = 0 - 1
2x = - 1
2x/2 = - 1/2. . <=. .not used
x = - 1/2
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X - 3 = 0
x - 3 + 3 + 0 + 3
x = 3
The answer is x = 3
Insert the x value into the euation
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2x² - 5x - 3 = 0
2(3)² - 5(3) - 3 = 0
2(9) - 15 - 3 = 0
18 - 18 = 0
0 = 0
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2007-01-10 03:02:09
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answer #1
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answered by SAMUEL D 7
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P(x)=2x^2-5x-3
The polynomial in U shape because the coefficient of x^2 is positive.
Let's find the points in which P(x) is 0.
2x^2-5x-3=0
x1=-0,5
x2=3
Between x=-0,5 and x=3, the sign of the polynomial is negative.
When x=-0,5, the polynomial is 0.
When x=3, the polynomial is 0.
When x<-0,5, the sign of the polynomial is positive.
When x>3, the sign of the polynomial is positive.
2007-01-10 01:35:32
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answer #2
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answered by Salih D 1
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OK, set the polynomial equal to zero, solve for x
(2x²-5x-3)=0
(x-3)(2x+1)=0
x=3, x=-1/2
At those points, x is zero. Between them, the curve is either positive or negative' outside of them, it's the opposite.
0 is between those points. At x=0, f(x) is -3.
So, curve is positive (-∞, -1/2) and (3,∞), negative on (-1/2,3) and zero as listed above.
2007-01-10 01:41:20
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answer #3
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answered by bequalming 5
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y = 0 <=> x = 3 or x = -1/2
with every real values of x within (-1/2,3) the sign of polynomial will be negative, and will be positive with the rest
2007-01-10 01:45:21
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answer #4
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answered by James Chan 4
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sign of the given polynomial is positive for all real values of x
2007-01-14 00:37:24
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answer #5
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answered by Anonymous
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(2x+1)(x-3) zero at -1/2 & at +3
x<-1/2, +
x>3, +
elsewere -
2007-01-10 01:46:17
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answer #6
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answered by Anonymous
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I'd just go with pi, thats usually a pretty good guess for any math question
2007-01-10 01:37:30
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answer #7
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answered by klubbandy575 2
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2x^2-5x-3
2x^2-6x+1x-3
(2x^2-6x)+(1x-3)
2x(x-3)+(x-3)
(2x+1)(x-3)
x= 3 and -1/2
2007-01-10 01:35:30
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answer #8
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answered by 7
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