[tex] \frac{1}{2} a + \frac{2}{3} a = 5 \\ \frac{3}{6} a + \frac{4}{6} a = 5 \\ \frac{7}{6} a = 5 \\ a = 5 \div \frac{7}{6} \\ a = \frac{5 \times 6}{7} \\ a = \frac{30}{7} \\ a = 4\frac{2}{7} [/tex]

[tex] \frac{3}{4} z + 32 = \frac{2}{5} z + 2.5 \\ \frac{3}{4} z - \frac{2}{5} z = 2.5 - 32 \\ \frac{15}{20} z - \frac{8}{20} z = - 29.5 \\ \frac{7}{20} z = - 29.5 \\ z = - 29.5 \div \frac{7}{20} \\ x = - \frac{59 \times 20}{2 \times 7} \\ x = - \frac{590}{7} \\ x = - 84 \frac{2}{7} [/tex]

Ответ:

а)30/7

г)2

Пошаговое объяснение:

а)1/2а+2/3а=5

3+4/6а=5

7/6а=5

а=5*6/1*7

а=30/7

г)3/4z+3,2=2/5 z+2,5

3/4z-2/5z=2,5-3,2

15-8/20z=-0,7

7/20z=0,7

z=7*20/10*7

z=2