2.1x-4.7x(x-4)=14.3

Solution for 2.1x-4.7x(x-4)=14.3 equation:

2.1x-4.7x(x-4)=14.3

We move all terms to the left:

2.1x-4.7x(x-4)-(14.3)=0

We add all the numbers together, and all the variables

2.1x-4.7x(x-4)-14.3=0

We multiply parentheses

-4x^2+2.1x+16x-14.3=0

We add all the numbers together, and all the variables

-4x^2+18.1x-14.3=0

a = -4; b = 18.1; c = -14.3;
Δ = b2-4ac
Δ = 18.12-4·(-4)·(-14.3)
Δ = 98.81
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{-(18.1)-\sqrt{98.81}}{2*-4}=\frac{-18.1-\sqrt{98.81}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18.1)+\sqrt{98.81}}{2*-4}=\frac{-18.1+\sqrt{98.81}}{-8}
$