.4=(x*x)+1.34x

Solution for .4=(x*x)+1.34x equation:

.4=(x*x)+1.34x

We move all terms to the left:

.4-((x*x)+1.34x)=0

We add all the numbers together, and all the variables

-((+x*x)+1.34x)+.4=0

We add all the numbers together, and all the variables

-((+x*x)+1.34x)+0.4=0


We calculate terms in parentheses: -((+x*x)+1.34x), so:

(+x*x)+1.34x

We add all the numbers together, and all the variables

1.34x+(+x*x)

We get rid of parentheses

1.34x+x*x

Wy multiply elements

x^2+1.34x

Back to the equation:

-(x^2+1.34x)


We get rid of parentheses

-x^2-1.34x+0.4=0

We add all the numbers together, and all the variables

-1x^2-1.34x+0.4=0

a = -1; b = -1.34; c = +0.4;
Δ = b2-4ac
Δ = -1.342-4·(-1)·0.4
Δ = 3.3956
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{-(-1.34)-\sqrt{3.3956}}{2*-1}=\frac{1.34-\sqrt{3.3956}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.34)+\sqrt{3.3956}}{2*-1}=\frac{1.34+\sqrt{3.3956}}{-2}
$