-21x=-63x^2

Solution for -21x=-63x^2 equation:

-21x=-63x^2

We move all terms to the left:

-21x-(-63x^2)=0

We get rid of parentheses

63x^2-21x=0

a = 63; b = -21; c = 0;
Δ = b2-4ac
Δ = -212-4·63·0
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-21)-21}{2*63}=\frac{0}{126}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+21}{2*63}=\frac{42}{126}
=1/3
$