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x^{2}-10x+19=0
Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.
x=\frac{-\left(-10\right)±\sqrt{\left(-10\right)^{2}-4\times 19}}{2}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-\left(-10\right)±\sqrt{100-4\times 19}}{2}
Square -10.
x=\frac{-\left(-10\right)±\sqrt{100-76}}{2}
Multiply -4 times 19.
x=\frac{-\left(-10\right)±\sqrt{24}}{2}
Add 100 to -76.
x=\frac{-\left(-10\right)±2\sqrt{6}}{2}
Take the square root of 24.
x=\frac{10±2\sqrt{6}}{2}
The opposite of -10 is 10.
x=\frac{2\sqrt{6}+10}{2}
Now solve the equation x=\frac{10±2\sqrt{6}}{2} when ± is plus. Add 10 to 2\sqrt{6}.
x=\sqrt{6}+5
Divide 10+2\sqrt{6} by 2.
x=\frac{10-2\sqrt{6}}{2}
Now solve the equation x=\frac{10±2\sqrt{6}}{2} when ± is minus. Subtract 2\sqrt{6} from 10.
x=5-\sqrt{6}
Divide 10-2\sqrt{6} by 2.
x^{2}-10x+19=\left(x-\left(\sqrt{6}+5\right)\right)\left(x-\left(5-\sqrt{6}\right)\right)
Factor the original expression using ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Substitute 5+\sqrt{6} for x_{1} and 5-\sqrt{6} for x_{2}.
x ^ 2 -10x +19 = 0
Quadratic equations such as this one can be solved by a new direct factoring method that does not require guess work. To use the direct factoring method, the equation must be in the form x^2+Bx+C=0.
r + s = 10 rs = 19
Let r and s be the factors for the quadratic equation such that x^2+Bx+C=(x−r)(x−s) where sum of factors (r+s)=−B and the product of factors rs = C
r = 5 - u s = 5 + u
Two numbers r and s sum up to 10 exactly when the average of the two numbers is \frac{1}{2}*10 = 5. You can also see that the midpoint of r and s corresponds to the axis of symmetry of the parabola represented by the quadratic equation y=x^2+Bx+C. The values of r and s are equidistant from the center by an unknown quantity u. Express r and s with respect to variable u. <div style='padding: 8px'><img src='https://opalmath.azureedge.net/customsolver/quadraticgraph.png' style='width: 100%;max-width: 700px' /></div>
(5 - u) (5 + u) = 19
To solve for unknown quantity u, substitute these in the product equation rs = 19
25 - u^2 = 19
Simplify by expanding (a -b) (a + b) = a^2 – b^2
-u^2 = 19-25 = -6
Simplify the expression by subtracting 25 on both sides
u^2 = 6 u = \pm\sqrt{6} = \pm \sqrt{6}
Simplify the expression by multiplying -1 on both sides and take the square root to obtain the value of unknown variable u
r =5 - \sqrt{6} = 2.551 s = 5 + \sqrt{6} = 7.449
The factors r and s are the solutions to the quadratic equation. Substitute the value of u to compute the r and s.