(0.6x^2)=(8x^2)-6.9

Solution for (0.6x^2)=(8x^2)-6.9 equation:

(0.6x^2)=(8x^2)-6.9

We move all terms to the left:

(0.6x^2)-((8x^2)-6.9)=0

We get rid of parentheses

0.6x^2-8x^2+6.9=0

We add all the numbers together, and all the variables

-7.4x^2+6.9=0

a = -7.4; b = 0; c = +6.9;
Δ = b2-4ac
Δ = 02-4·(-7.4)·6.9
Δ = 204.24
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)-\sqrt{204.24}}{2*-7.4}=\frac{0-\sqrt{204.24}}{-14.8}
=-\frac{\sqrt{}}{-14.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{204.24}}{2*-7.4}=\frac{0+\sqrt{204.24}}{-14.8}
=\frac{\sqrt{}}{-14.8}
$