(x+1)(x+2)=1722

Solution for (x+1)(x+2)=1722 equation:

(x+1)(x+2)=1722

We move all terms to the left:

(x+1)(x+2)-(1722)=0

We multiply parentheses ..

(+x^2+2x+x+2)-1722=0

We get rid of parentheses

x^2+2x+x+2-1722=0

We add all the numbers together, and all the variables

x^2+3x-1720=0

a = 1; b = 3; c = -1720;
Δ = b2-4ac
Δ = 32-4·1·(-1720)
Δ = 6889
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6889}=83$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-83}{2*1}=\frac{-86}{2}
=-43
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+83}{2*1}=\frac{80}{2}
=40
$