(5x+10)3x=20

Solution for (5x+10)3x=20 equation:

(5x+10)3x=20

We move all terms to the left:

(5x+10)3x-(20)=0

We multiply parentheses

15x^2+30x-20=0

a = 15; b = 30; c = -20;
Δ = b2-4ac
Δ = 302-4·15·(-20)
Δ = 2100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2100}=\sqrt{100*21}=\sqrt{100}*\sqrt{21}=10\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-10\sqrt{21}}{2*15}=\frac{-30-10\sqrt{21}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+10\sqrt{21}}{2*15}=\frac{-30+10\sqrt{21}}{30}
$