(5x)2+8.5x=+20

Solution for (5x)2+8.5x=+20 equation:

(5x)2+8.5x=+20

We move all terms to the left:

(5x)2+8.5x-(+20)=0

We add all the numbers together, and all the variables

5x2+8.5x-20=0

We add all the numbers together, and all the variables

5x^2+8.5x-20=0

a = 5; b = 8.5; c = -20;
Δ = b2-4ac
Δ = 8.52-4·5·(-20)
Δ = 472.25
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{-(8.5)-\sqrt{472.25}}{2*5}=\frac{-8.5-\sqrt{472.25}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8.5)+\sqrt{472.25}}{2*5}=\frac{-8.5+\sqrt{472.25}}{10}
$