A=(r1+r2)=r1r2

Solution for A=(r1+r2)=r1r2 equation:

=(A1+A2)=A1A^2

We move all terms to the left:

-((A1+A2))=0

We add all the numbers together, and all the variables

-((+A+A^2))=0


We calculate terms in parentheses: -((+A+A^2)), so:

(+A+A^2)

We get rid of parentheses

A^2+A

Back to the equation:

-(A^2+A)


We get rid of parentheses

-A^2-A=0

We add all the numbers together, and all the variables

-1A^2-1A=0

a = -1; b = -1; c = 0;
Δ = b2-4ac
Δ = -12-4·(-1)·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-1}{2*-1}=\frac{0}{-2}
=0
$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+1}{2*-1}=\frac{2}{-2}
=-1
$