2+21a=11a^2

Solution for 2+21a=11a^2 equation:

2+21a=11a^2

We move all terms to the left:

2+21a-(11a^2)=0

determiningTheFunctionDomain
-11a^2+21a+2=0

a = -11; b = 21; c = +2;
Δ = b2-4ac
Δ = 212-4·(-11)·2
Δ = 529
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{529}=23$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-23}{2*-11}=\frac{-44}{-22}
=+2
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+23}{2*-11}=\frac{2}{-22}
=-1/11
$