0=-10x^2-130x+400

Solution for 0=-10x^2-130x+400 equation:

0=-10x^2-130x+400

We move all terms to the left:

0-(-10x^2-130x+400)=0

We add all the numbers together, and all the variables

-(-10x^2-130x+400)=0

We get rid of parentheses

10x^2+130x-400=0

a = 10; b = 130; c = -400;
Δ = b2-4ac
Δ = 1302-4·10·(-400)
Δ = 32900
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:

$\sqrt{\Delta}=\sqrt{32900}=\sqrt{100*329}=\sqrt{100}*\sqrt{329}=10\sqrt{329}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(130)-10\sqrt{329}}{2*10}=\frac{-130-10\sqrt{329}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(130)+10\sqrt{329}}{2*10}=\frac{-130+10\sqrt{329}}{20}
$