4 примера! Даю 15 балов!

1) $4 - \frac{u}{5} = \frac{4}{5}$ /*5

20 - u = 4

16 = u

2) $\frac{z}{10} + 1 = -10$

$\frac{z}{10} = -11$

-110 = z

3) $\frac{z}{5} = \frac{z}{10} + 1$

$\frac{z}{5} - \frac{z}{10} = 1$

$\frac{2z}{10} - \frac{z}{10} = 1$

$\frac{z}{10} = 1$

z = 10

4) $\frac{u}{2} - 3 = \frac{u}{4} + 5$

$\frac{u}{2} - \frac{u}{4} = 3 + 5$

$\frac{2u}{4} - \frac{u}{4} = 8$

$\frac{u}{4} = 8$

u = 32