Question

Упростите выражение $\frac{1}{z+2}- \frac{2}{3z}$

Answer 1

$\frac{1}{z+2} - \frac{2}{3z} = \frac{3z*1}{3z*(z+2)} - \frac{(z+2)*2}{(z+2)*3z} = \frac{3z-(z+2)*2}{3z*(z+2)} = \frac{3z-2z-4}{3z*(z+2)} = \frac{z-4}{3z^2+6z}$