-20X^2-58x+42x=0

Solution for -20X^2-58x+42x=0 equation:

-20X^2-58X+42X=0

We add all the numbers together, and all the variables

-20X^2-16X=0

a = -20; b = -16; c = 0;
Δ = b2-4ac
Δ = -162-4·(-20)·0
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-16}{2*-20}=\frac{0}{-40}
=0
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+16}{2*-20}=\frac{32}{-40}
=-4/5
$