$1,2x^2 + x = 0$
x(1,2x + 1) = 0
$x_1 = 0$
1,2x + 1 = 0
1,2x = −1
$x_2 = -\frac{1}{1,2} = -\frac{10}{12} = -\frac{5}{6}$

$1,6x + x^2 = 0$
x(1,6 + x) = 0
$x_1 = 0$
1,6 + x = 0
$x_2 = -1,6$

$0,5x^2 - x = 0$
x(0,5x − 1) = 0
$x_1 = 0$
0,5x − 1 = 0
0,5x = 1
x = 1 : 0,5
$x_2 = 2$

$5x^2 = x$
$5x^2 - x = 0$
x(5x − 1) = 0
$x_1 = 0$
5x − 1 = 0
5x = 1
x = 1 : 5
$x_2 = 0,2$

$1,6x^2 = 3x$
$1,6x^2 - 3x = 0$
x(1,6x − 3) = 0
$x_1 = 0$
1,6x − 3 = 0
1,6x = 3
$x_2 = \frac{3}{1,6} = \frac{30}{16} = \frac{15}{8} = 1\frac{7}{8}$

$x = x^2$
$x - x^2 = 0$
$x(1 - x) = 0$
$x_1 = 0$
1 − x = 0
−x = −1
$x_2 = 1$