x^2+2.4x+25=430

Solution for x^2+2.4x+25=430 equation:

x^2+2.4x+25=430

We move all terms to the left:

x^2+2.4x+25-(430)=0

We add all the numbers together, and all the variables

x^2+2.4x-405=0

a = 1; b = 2.4; c = -405;
Δ = b2-4ac
Δ = 2.42-4·1·(-405)
Δ = 1625.76
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{-(2.4)-\sqrt{1625.76}}{2*1}=\frac{-2.4-\sqrt{1625.76}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2.4)+\sqrt{1625.76}}{2*1}=\frac{-2.4+\sqrt{1625.76}}{2}
$