x^2+1.3x+0.84=-2x+4x+4.2

Solution for x^2+1.3x+0.84=-2x+4x+4.2 equation:

x^2+1.3x+0.84=-2x+4x+4.2

We move all terms to the left:

x^2+1.3x+0.84-(-2x+4x+4.2)=0

We add all the numbers together, and all the variables

x^2+1.3x-(2x+4.2)+0.84=0

We get rid of parentheses

x^2+1.3x-2x-4.2+0.84=0

We add all the numbers together, and all the variables

x^2-0.7x-3.36=0

a = 1; b = -0.7; c = -3.36;
Δ = b2-4ac
Δ = -0.72-4·1·(-3.36)
Δ = 13.93
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{-(-0.7)-\sqrt{13.93}}{2*1}=\frac{0.7-\sqrt{13.93}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.7)+\sqrt{13.93}}{2*1}=\frac{0.7+\sqrt{13.93}}{2}
$