x^2/3-7x-1=0

Solution for x^2/3-7x-1=0 equation:

x^2/3-7x-1=0

We multiply all the terms by the denominator


x^2-7x*3-1*3=0

We add all the numbers together, and all the variables

x^2-7x*3-3=0

Wy multiply elements

x^2-21x-3=0

a = 1; b = -21; c = -3;
Δ = b2-4ac
Δ = -212-4·1·(-3)
Δ = 453
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-21)-\sqrt{453}}{2*1}=\frac{21-\sqrt{453}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+\sqrt{453}}{2*1}=\frac{21+\sqrt{453}}{2}
$