A=(13x-5)(14x+1)

Solution for A=(13x-5)(14x+1) equation:

=(13A-5)(14A+1)

We move all terms to the left:

-((13A-5)(14A+1))=0

We multiply parentheses ..

-((+182A^2+13A-70A-5))=0


We calculate terms in parentheses: -((+182A^2+13A-70A-5)), so:

(+182A^2+13A-70A-5)

We get rid of parentheses

182A^2+13A-70A-5

We add all the numbers together, and all the variables

182A^2-57A-5

Back to the equation:

-(182A^2-57A-5)


We get rid of parentheses

-182A^2+57A+5=0

a = -182; b = 57; c = +5;
Δ = b2-4ac
Δ = 572-4·(-182)·5
Δ = 6889
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6889}=83$
$A_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(57)-83}{2*-182}=\frac{-140}{-364}
=5/13
$
$A_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(57)+83}{2*-182}=\frac{26}{-364}
=-1/14
$