2x-5x(x-4)=14

Solution for 2x-5x(x-4)=14 equation:

2x-5x(x-4)=14

We move all terms to the left:

2x-5x(x-4)-(14)=0

We multiply parentheses

-5x^2+2x+20x-14=0

We add all the numbers together, and all the variables

-5x^2+22x-14=0

a = -5; b = 22; c = -14;
Δ = b2-4ac
Δ = 222-4·(-5)·(-14)
Δ = 204
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:

$\sqrt{\Delta}=\sqrt{204}=\sqrt{4*51}=\sqrt{4}*\sqrt{51}=2\sqrt{51}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(22)-2\sqrt{51}}{2*-5}=\frac{-22-2\sqrt{51}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(22)+2\sqrt{51}}{2*-5}=\frac{-22+2\sqrt{51}}{-10}
$