x = [- b ± √ (b² - 4ac)] / 2a
a = 3, b = - 2 , c = -2
x = [ 2 ± √ (4 + 24 ) ] / 6
x = [ 2 ±√ 28 ] / 6
x = [ 2 ± 2√ 7 ] / 6
x = 1/3 ± (1/3).√ 7
x = 1/3.(1 ± √7 )
2007-02-28 03:39:01
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answer #1
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answered by Como 7
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Since our equation is set equal to 0, we can start right in. Now, the quadratic formula is (-b±âb²-4ac))/2a.
Now, it's much less confusing if we use another formula along with this one that let's us know the values of the variables. That formula is ax²+bx+c=0, which is directly related to any quadratic formula (this formula is directly related to your formula 3x²-2x-2=0).
So, using this extra formula, we realize that a=3, because 3 is the number infront of x². b=-2, because +(-2)=-2, and -2 is the number infront of x. Finally, c=-2 because +(-2)=-2 and -2 is the number not attatced to an x term on the right side of the equation.
So, now we plug in these variables in the quadratic formula:
(-(-2)±â((-2)²-4(3*-2)))/2(3)
First off, we know that -(-2)=2. Next, since we have to use PEMDAS in the square root in the denominator, we simplify the parenthesis first. We know that (3*-2)=-6. Next, we know that (-2)²=4, and we know that -4(-6)=24. Finally, in the denominator, we see that 2(3)=6. Therefore our equation is now:
(2屉(4+24))/6.
Now, we know that 24+4=28, and, simplifying â28, we get 2â7. Therefore our equation is now:
(2±2â7)/6.
Therefore, your answer would be
2±2â7
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6
We then see that the highest number the whole numbers can be divided by is 2. Therefore, we divide both 2's and the 6 by 2, therefore getting our answer:
x=(1屉7)/3
There you go. I'm glad I could help. :)
2007-02-28 15:20:17
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answer #2
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answered by iamanicecaringfriend 3
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-b plus or minus the squareroot of b^2 - 4ac divided by 2a
so a=3
b=-2
and c= -2
2 plus or minus the squareroot of -2^2 - 4(3)(-2)
divided bye a(3)
2 plus or minus square root of 4 +24 divides by 6
2 +/- square root of 28 divided by 6
2 + 5.29150262 divided by 6 and
2 - 5.29150262 divided by 6
3.29150262 divided by 6
7.29150262 divided by 6
ANSWERS:
0.54858377
and
1.21525044
i think
2007-02-28 11:38:55
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answer #3
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answered by samantha g 2
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[-b +/- square root ( b^2-4ac)]/2a
a=3 b=-2 c=-2
[2+/- sqrt(4+24)]/6
[2+ sqrt 28]/6 or [2- sqrt 28]/6
(2+5.3)/6= 1.2 or (2- 5.3)/6 = -0.55
the closest answer after pluggin the x's is -0.55
2007-02-28 11:47:28
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answer #4
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answered by Phy A 5
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(3x-1)(x + 2)=0
x= -1/3 or x = -2
2007-02-28 12:06:08
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answer #5
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answered by Blue Moon 3
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ax^2 + bx + c =
x = (-b +/- sqrt(b^2-4ac) )/2a
a = 3, b = -2, c = -2
2007-02-28 11:30:45
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answer #6
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answered by Morgy 4
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x= [-(-2)+/-â(4-(4*3*(-2))]/6
x=[2+/-â(4+24)]/6
x=[2+/-2â7]/6
2007-02-28 11:29:44
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answer #7
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answered by Maths Rocks 4
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x=-(-2)+/-[(4+24)^1/2]/9
=2/6+/-2/6rt7
=1/3(1+rt7);1/3(1-rt7)
2007-02-28 11:28:20
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answer #8
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answered by raj 7
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