x^2+5x-14=0 equation
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The solution
Detail solution
This equation is of the form
a*x^2 + b*x + c = 0 A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
x 1 = D − b 2 a x_{1} = \frac{\sqrt{D} - b}{2 a} x 1 = 2 a D − b x 2 = − D − b 2 a x_{2} = \frac{- \sqrt{D} - b}{2 a} x 2 = 2 a − D − b where D = b^2 - 4*a*c - it is the discriminant.
Because
a = 1 a = 1 a = 1 b = 5 b = 5 b = 5 c = − 14 c = -14 c = − 14 , then
D = b^2 - 4 * a * c = (5)^2 - 4 * (1) * (-14) = 81 Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a) x2 = (-b - sqrt(D)) / (2*a) or
x 1 = 2 x_{1} = 2 x 1 = 2 Simplify x 2 = − 7 x_{2} = -7 x 2 = − 7 Simplify
Vieta's Theorem
it is reduced quadratic equation
p x + q + x 2 = 0 p x + q + x^{2} = 0 p x + q + x 2 = 0 where
p = b a p = \frac{b}{a} p = a b p = 5 p = 5 p = 5 q = c a q = \frac{c}{a} q = a c q = − 14 q = -14 q = − 14 Vieta Formulas
x 1 + x 2 = − p x_{1} + x_{2} = - p x 1 + x 2 = − p x 1 x 2 = q x_{1} x_{2} = q x 1 x 2 = q x 1 + x 2 = − 5 x_{1} + x_{2} = -5 x 1 + x 2 = − 5 x 1 x 2 = − 14 x_{1} x_{2} = -14 x 1 x 2 = − 14
The graph
0 5 -25 -20 -15 -10 -5 10 15 -250 250
Sum and product of roots
[src]
( − 7 + 0 ) + 2 \left(-7 + 0\right) + 2 ( − 7 + 0 ) + 2
1 ( − 7 ) 2 1 \left(-7\right) 2 1 ( − 7 ) 2