15x2-3x-9=0

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Solution for 15x2-3x-9=0 equation:



15x^2-3x-9=0
a = 15; b = -3; c = -9;
Δ = b2-4ac
Δ = -32-4·15·(-9)
Δ = 549
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:
$\sqrt{\Delta}=\sqrt{549}=\sqrt{9*61}=\sqrt{9}*\sqrt{61}=3\sqrt{61}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-3\sqrt{61}}{2*15}=\frac{3-3\sqrt{61}}{30} $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+3\sqrt{61}}{2*15}=\frac{3+3\sqrt{61}}{30} $

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