A=(5x+6)(6x+2)

Solution for A=(5x+6)(6x+2) equation:

=(5A+6)(6A+2)

We move all terms to the left:

-((5A+6)(6A+2))=0

We multiply parentheses ..

-((+30A^2+10A+36A+12))=0


We calculate terms in parentheses: -((+30A^2+10A+36A+12)), so:

(+30A^2+10A+36A+12)

We get rid of parentheses

30A^2+10A+36A+12

We add all the numbers together, and all the variables

30A^2+46A+12

Back to the equation:

-(30A^2+46A+12)


We get rid of parentheses

-30A^2-46A-12=0

a = -30; b = -46; c = -12;
Δ = b2-4ac
Δ = -462-4·(-30)·(-12)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-46)-26}{2*-30}=\frac{20}{-60}
=-1/3
$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-46)+26}{2*-30}=\frac{72}{-60}
=-1+1/5
$