Question 116121
Let's begin this problem by getting it into the standard quadratic form:
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{{{ax^2 + bx + c = 0}}}
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You can get it into the quadratic form by adding 1 to both sides of the equation to transform it
to:
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{{{2x^2 + 10x +1 = 0}}}
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By comparing this to the standard form above you can see that "a" corresponds to 2, 
b corresponds to 10, and c corresponds to 1.
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If you have trouble factoring the original problem or you suspect that the problem may have a
set of complex answers, a good method to use on a quadratic equation is the quadratic formula
which says that for the form:
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{{{ax^2 + bx + c = 0}}}
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the solution is given by:
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{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
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for this problem, if you substitute +2 for a, +10 for b, and +1 for c, you get the solution 
as:
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{{{x = (-(10) +- sqrt( 10^2-4*2*1 ))/(2*2) }}}
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Inside the radical sign the {{{10^2 - 4*2*1}}} simplifies to {{{100 - 8 = 92}}}. Since this is
positive you know that the two values of x will be real. The square root of 92 is 9.591663047. 
Substituting this into the equation for x results in:
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{{{x = (-(10) +- 9.591663047)/(2*2) }}}
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The -(10) is equivalent to -10 and in the denominator the 2*2 = 4. These two simplify the
equation for x to:
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{{{x = (-10 +- 9.591663047)/4}}}
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This means the two answers for x are:
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{{{x = (-10 + 9.591663047)/4 = -0.408336953/4 = -0.102084238}}}
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and 
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{{{x = (-10 - 9.591663047)/4  = -19.591663047/4 = -4.897915762}}}
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Hope this helps you to do the problem. If you want to get the answers in terms of radicals,
you can replace {{{sqrt(92)}}} by {{{2*sqrt(23)}}} and your answers will be:
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{{{x = (-(10) +- 2*sqrt(23))/(2*2) }}}
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Which you can simplify down to:
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{{{x = (-5+-sqrt(23))/2}}}
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