(X)=2.15(2x2-4x-6)

Solution for (X)=2.15(2x2-4x-6) equation:

(X)=2.15(2X^2-4X-6)

We move all terms to the left:

(X)-(2.15(2X^2-4X-6))=0


We calculate terms in parentheses: -(2.15(2X^2-4X-6)), so:

2.15(2X^2-4X-6)

We multiply parentheses

4.3X^2-8.6X-12.9

Back to the equation:

-(4.3X^2-8.6X-12.9)


We get rid of parentheses

-4.3X^2+X+8.6X+12.9=0

We add all the numbers together, and all the variables

-4.3X^2+9.6X+12.9=0

a = -4.3; b = 9.6; c = +12.9;
Δ = b2-4ac
Δ = 9.62-4·(-4.3)·12.9
Δ = 314.04
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{-(9.6)-\sqrt{314.04}}{2*-4.3}=\frac{-9.6-\sqrt{314.04}}{-8.6}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9.6)+\sqrt{314.04}}{2*-4.3}=\frac{-9.6+\sqrt{314.04}}{-8.6}
$