-7x(1-8x)=105

Solution for -7x(1-8x)=105 equation:

-7x(1-8x)=105

We move all terms to the left:

-7x(1-8x)-(105)=0

We add all the numbers together, and all the variables

-7x(-8x+1)-105=0

We multiply parentheses

56x^2-7x-105=0

a = 56; b = -7; c = -105;
Δ = b2-4ac
Δ = -72-4·56·(-105)
Δ = 23569
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:

$\sqrt{\Delta}=\sqrt{23569}=\sqrt{49*481}=\sqrt{49}*\sqrt{481}=7\sqrt{481}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-7\sqrt{481}}{2*56}=\frac{7-7\sqrt{481}}{112}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+7\sqrt{481}}{2*56}=\frac{7+7\sqrt{481}}{112}
$