-7a(a-3)=11-7a

Solution for -7a(a-3)=11-7a equation:

-7a(a-3)=11-7a

We move all terms to the left:

-7a(a-3)-(11-7a)=0

We add all the numbers together, and all the variables

-7a(a-3)-(-7a+11)=0

We multiply parentheses

-7a^2+21a-(-7a+11)=0

We get rid of parentheses

-7a^2+21a+7a-11=0

We add all the numbers together, and all the variables

-7a^2+28a-11=0

a = -7; b = 28; c = -11;
Δ = b2-4ac
Δ = 282-4·(-7)·(-11)
Δ = 476
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{476}=\sqrt{4*119}=\sqrt{4}*\sqrt{119}=2\sqrt{119}$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-2\sqrt{119}}{2*-7}=\frac{-28-2\sqrt{119}}{-14}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+2\sqrt{119}}{2*-7}=\frac{-28+2\sqrt{119}}{-14}
$