x(x+1.4)=13.95

Solution for x(x+1.4)=13.95 equation:

x(x+1.4)=13.95

We move all terms to the left:

x(x+1.4)-(13.95)=0

We add all the numbers together, and all the variables

x(x+1.4)-13.95=0

We multiply parentheses

x^2+1.4x-13.95=0

a = 1; b = 1.4; c = -13.95;
Δ = b2-4ac
Δ = 1.42-4·1·(-13.95)
Δ = 57.76
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{-(1.4)-\sqrt{57.76}}{2*1}=\frac{-1.4-\sqrt{57.76}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.4)+\sqrt{57.76}}{2*1}=\frac{-1.4+\sqrt{57.76}}{2}
$