4x(x-3.1)=9.2

Solution for 4x(x-3.1)=9.2 equation:

4x(x-3.1)=9.2

We move all terms to the left:

4x(x-3.1)-(9.2)=0

We add all the numbers together, and all the variables

4x(x-3.1)-9.2=0

We multiply parentheses

4x^2-12.4x-9.2=0

a = 4; b = -12.4; c = -9.2;
Δ = b2-4ac
Δ = -12.42-4·4·(-9.2)
Δ = 300.96
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{-(-12.4)-\sqrt{300.96}}{2*4}=\frac{12.4-\sqrt{300.96}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12.4)+\sqrt{300.96}}{2*4}=\frac{12.4+\sqrt{300.96}}{8}
$