26x2-208x+390=0

Solution for 26x2-208x+390=0 equation:

26x^2-208x+390=0

a = 26; b = -208; c = +390;
Δ = b2-4ac
Δ = -2082-4·26·390
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-208)-52}{2*26}=\frac{156}{52}
=3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-208)+52}{2*26}=\frac{260}{52}
=5
$