(x)(x+3)=2.79

Solution for (x)(x+3)=2.79 equation:

(x)(x+3)=2.79

We move all terms to the left:

(x)(x+3)-(2.79)=0

We add all the numbers together, and all the variables

x(x+3)-2.79=0

We multiply parentheses

x^2+3x-2.79=0

a = 1; b = 3; c = -2.79;
Δ = b2-4ac
Δ = 32-4·1·(-2.79)
Δ = 20.16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-\sqrt{20.16}}{2*1}=\frac{-3-\sqrt{20.16}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{20.16}}{2*1}=\frac{-3+\sqrt{20.16}}{2}
$