(x+5)7x=20

Solution for (x+5)7x=20 equation:

(x+5)7x=20

We move all terms to the left:

(x+5)7x-(20)=0

We multiply parentheses

7x^2+35x-20=0

a = 7; b = 35; c = -20;
Δ = b2-4ac
Δ = 352-4·7·(-20)
Δ = 1785
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{-(35)-\sqrt{1785}}{2*7}=\frac{-35-\sqrt{1785}}{14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+\sqrt{1785}}{2*7}=\frac{-35+\sqrt{1785}}{14}
$