2x^2-30x+25=0

Solution for 2x^2-30x+25=0 equation:

2x^2-30x+25=0

a = 2; b = -30; c = +25;
Δ = b2-4ac
Δ = -302-4·2·25
Δ = 700
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:

$\sqrt{\Delta}=\sqrt{700}=\sqrt{100*7}=\sqrt{100}*\sqrt{7}=10\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{7}}{2*2}=\frac{30-10\sqrt{7}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{7}}{2*2}=\frac{30+10\sqrt{7}}{4}
$