25=3x^2-10x

Solution for 25=3x^2-10x equation:

25=3x^2-10x

We move all terms to the left:

25-(3x^2-10x)=0

We get rid of parentheses

-3x^2+10x+25=0

a = -3; b = 10; c = +25;
Δ = b2-4ac
Δ = 102-4·(-3)·25
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-20}{2*-3}=\frac{-30}{-6}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+20}{2*-3}=\frac{10}{-6}
=-1+2/3
$