Answer
The solution is {$\frac{-2 \pm \sqrt{10}}{2}$}
Work Step by Step
$0.2x^2$ $+ 0.4x$ $- 0.3$ = $0$
$2x^2$ $+ 4x$ $- 3$ = $0$
$x$ $=$ $\frac{-4 \pm \sqrt{4^2 - (4)(2)(-3)}}{2 (2)}$ (Quadratic formula)
$x$ $=$ $\frac{-4 \pm \sqrt{16 + 24}}{4}$
$x$ $=$ $\frac{-4 \pm 2\sqrt{10}}{4}$
$x$ $=$ $\frac{-2 \pm \sqrt{10}}{2}$
The solution is {$\frac{-2 \pm \sqrt{10}}{2}$}