To solve the equation, factor x^2-2x-8 using formula x^2+left(a+b ight)x+ab=left(x+a ight)left(x+b ight). To find a and b, set up a system to be solved.

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Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -8.
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https://math.stackexchange.com/questions/1217750/why-are-there-four-solutions-to-x2-2x-8-0-in-mathbbr-or-am-i-wrong
Your mistake is to assume that for a,b,cinmathbbR, ab=cquadimpliesquad a=cquad extorquad b=c. ag1 This is not true in general. For example 2 imesfrac12=1, but neither 2=1 ...
3x2-2x-8=0 Two solutions were found : x = -4/3 = -1.333 x = 2 Step by step solution : Step 1 :Equation at the end of step 1 : (3x2 - 2x) - 8 = 0 Step 2 :Trying to factor by splitting ns ...
4x2-2x-8=0 Two solutions were found : x =(1-√33)/4=-1.186 x =(1+√33)/4= 1.686 Step by step solution : Step 1 :Equation at the end of step 1 : (22x2 - 2x) - 8 = 0 Step 2 : Step 3 ...
5x2-2x-8=0 Two solutions were found : x =(2-√164)/10=(1-√ 41 )/5= -1.081 x =(2+√164)/10=(1+√ 41 )/5= 1.481 Step by step solution : Step 1 :Equation at the end of step 1 : (5x2 - 2x) - 8 = ...
9x2-2x-8=0 Two solutions were found : x =(2-√292)/18=(1-√ 73 )/9= -0.838 x =(2+√292)/18=(1+√ 73 )/9= 1.060 Step by step solution : Step 1 :Equation at the end of step 1 : (32x2 - 2x) - 8 ...
x2-2x-8=7 Two solutions were found : x = 5 x = -3 Rearrange: Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation : ...
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To solve the equation, factor x^2-2x-8 using formula x^2+left(a+b ight)x+ab=left(x+a ight)left(x+b ight). To find a and b, set up a system to be solved.
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -8.
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^2+ax+bx-8. To find a and b, set up a system to be solved.
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -8.
All equations of the form ax^2+bx+c=0 can be solved using the quadratic formula: frac-b±sqrtb^2-4ac2a. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
This equation is in standard form: ax^2+bx+c=0. Substitute 1 for a, -2 for b, and -8 for c in the quadratic formula, frac-b±sqrtb^2-4ac2a.
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^2+bx=c.

See more: The Greatest Integer Function Is Defined By Int(X) = The Greatest Integer That Is


Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
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