(25x)2-30x+7=0

Solution for (25x)2-30x+7=0 equation:

(25x)2-30x+7=0

We add all the numbers together, and all the variables

25x^2-30x+7=0

a = 25; b = -30; c = +7;
Δ = b2-4ac
Δ = -302-4·25·7
Δ = 200
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:

$\sqrt{\Delta}=\sqrt{200}=\sqrt{100*2}=\sqrt{100}*\sqrt{2}=10\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{2}}{2*25}=\frac{30-10\sqrt{2}}{50}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{2}}{2*25}=\frac{30+10\sqrt{2}}{50}
$