-51x+210=-3x^2

Solution for -51x+210=-3x^2 equation:

-51x+210=-3x^2

We move all terms to the left:

-51x+210-(-3x^2)=0

We get rid of parentheses

3x^2-51x+210=0

a = 3; b = -51; c = +210;
Δ = b2-4ac
Δ = -512-4·3·210
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-51)-9}{2*3}=\frac{42}{6}
=7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-51)+9}{2*3}=\frac{60}{6}
=10
$