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(15x-1)(6x+1,2)=0 equation

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Numerical solution:

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The solution

You have entered [src] 
(15*x - 1)*(6*x + 6/5) = 0
(6x+65)(15x−1)=0\left(6 x + \frac{6}{5}\right) \left(15 x - 1\right) = 0
Simplify
Detail solution
Expand the expression in the equation
(6x+65)(15x−1)=0\left(6 x + \frac{6}{5}\right) \left(15 x - 1\right) = 0
We get the quadratic equation
90x2+12x−65=090 x^{2} + 12 x - \frac{6}{5} = 0
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:
x1=D−b2ax_{1} = \frac{\sqrt{D} - b}{2 a}
x2=−D−b2ax_{2} = \frac{- \sqrt{D} - b}{2 a}
where D = b^2 - 4*a*c - it is the discriminant.
Because
a=90a = 90
b=12b = 12
c=−65c = - \frac{6}{5}
, then
D = b^2 - 4 * a * c = 

(12)^2 - 4 * (90) * (-6/5) = 576

Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)

x2 = (-b - sqrt(D)) / (2*a)

or
x1=115x_{1} = \frac{1}{15}
x2=−15x_{2} = - \frac{1}{5}
Rapid solution [src] 
x1 = -1/5
x1=−15x_{1} = - \frac{1}{5} 
x2 = 1/15
x2=115x_{2} = \frac{1}{15} 
x2 = 1/15
Sum and product of roots [src] 
sum
-1/5 + 1/15
−15+115- \frac{1}{5} + \frac{1}{15} 
=
-2/15
−215- \frac{2}{15} 
product
-1  
----
5*15
−175- \frac{1}{75} 
=
-1/75
−175- \frac{1}{75} 
-1/75
Numerical answer [src] 
x1 = -0.2
x2 = 0.0666666666666667
x2 = 0.0666666666666667
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