0=1000-260x+12x^2

Solution for 0=1000-260x+12x^2 equation:

0=1000-260x+12x^2

We move all terms to the left:

0-(1000-260x+12x^2)=0

We add all the numbers together, and all the variables

-(1000-260x+12x^2)=0

We get rid of parentheses

-12x^2+260x-1000=0

a = -12; b = 260; c = -1000;
Δ = b2-4ac
Δ = 2602-4·(-12)·(-1000)
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(260)-140}{2*-12}=\frac{-400}{-24}
=16+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(260)+140}{2*-12}=\frac{-120}{-24}
=+5
$