Zlomky

$$ \frac{x}{3} - 20 = \frac{x}{7} $$ $$ 7x - 420 = 3x $$ $$ 4x - 420 = 0 $$ $$ 4x = 420 $$ $$ x = 105

$$ \frac{x}{5} + \frac{x}{3} + \frac{2x}{9} + \frac{x}{6} = \frac{18x}{90} + \frac{30x}{90} + \frac{20x}{90} + \frac{15x}{90} = \frac{83x}{90}