X*x+56x-105=0

Solution for X*x+56x-105=0 equation:

X*X+56X-105=0

We add all the numbers together, and all the variables

56X+X*X-105=0

Wy multiply elements

X^2+56X-105=0

a = 1; b = 56; c = -105;
Δ = b2-4ac
Δ = 562-4·1·(-105)
Δ = 3556
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:

$\sqrt{\Delta}=\sqrt{3556}=\sqrt{4*889}=\sqrt{4}*\sqrt{889}=2\sqrt{889}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-2\sqrt{889}}{2*1}=\frac{-56-2\sqrt{889}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+2\sqrt{889}}{2*1}=\frac{-56+2\sqrt{889}}{2}
$