3(x+1)4x=26

Solution for 3(x+1)4x=26 equation:

3(x+1)4x=26

We move all terms to the left:

3(x+1)4x-(26)=0

We multiply parentheses

12x^2+12x-26=0

a = 12; b = 12; c = -26;
Δ = b2-4ac
Δ = 122-4·12·(-26)
Δ = 1392
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:

$\sqrt{\Delta}=\sqrt{1392}=\sqrt{16*87}=\sqrt{16}*\sqrt{87}=4\sqrt{87}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-4\sqrt{87}}{2*12}=\frac{-12-4\sqrt{87}}{24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+4\sqrt{87}}{2*12}=\frac{-12+4\sqrt{87}}{24}
$