(20x)+(5x^2)=385

Solution for (20x)+(5x^2)=385 equation:

(20x)+(5x^2)=385

We move all terms to the left:

(20x)+(5x^2)-(385)=0

determiningTheFunctionDomain
5x^2+20x-385=0

a = 5; b = 20; c = -385;
Δ = b2-4ac
Δ = 202-4·5·(-385)
Δ = 8100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8100}=90$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-90}{2*5}=\frac{-110}{10}
=-11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+90}{2*5}=\frac{70}{10}
=7
$