90=(6x+4)10x

Solution for 90=(6x+4)10x equation:

90=(6x+4)10x

We move all terms to the left:

90-((6x+4)10x)=0


We calculate terms in parentheses: -((6x+4)10x), so:

(6x+4)10x

We multiply parentheses

60x^2+40x

Back to the equation:

-(60x^2+40x)


We get rid of parentheses

-60x^2-40x+90=0

a = -60; b = -40; c = +90;
Δ = b2-4ac
Δ = -402-4·(-60)·90
Δ = 23200
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:

$\sqrt{\Delta}=\sqrt{23200}=\sqrt{400*58}=\sqrt{400}*\sqrt{58}=20\sqrt{58}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-20\sqrt{58}}{2*-60}=\frac{40-20\sqrt{58}}{-120}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+20\sqrt{58}}{2*-60}=\frac{40+20\sqrt{58}}{-120}
$