Ответ:

1)

\(a=17\frac{5}{6}:15\frac{2}{7}:\frac{7}{90}+25\)

\(a=\frac{107}{6}:\frac{107}{7}:\frac{7}{90}+25=\frac{7}{6}\cdot\frac{7}{107}\) емес, бөлшектерді ретімен есептейміз:

\(\frac{107}{6}:\frac{107}{7}=\frac{7}{6}\),

\(\frac{7}{6}:\frac{7}{90}=15\), сондықтан \(a=15+25=40\).

\(c=29\frac{2}{9}:20\frac{3}{13}\cdot0,45+3,35\)

\(c=\frac{263}{9}:\frac{263}{13}\cdot\frac{9}{20}+3,35=\frac{13}{9}\cdot\frac{9}{20}+3,35=0,65+3,35=4\).

Пайызын табамыз:

\(\frac{c}{a}\cdot100\%=\frac{4}{40}\cdot100\%=10\%\).

2)

\(a=5^3:\frac{5}{19}\cdot0,06+31,5=125:\frac{5}{19}\cdot0,06+31,5=475\cdot0,06+31,5=28,5+31,5=60\).

\(c=4^5:146\frac{2}{7}\cdot9,6-148,8\cdot0,25\)

\(c=1024:\frac{1024}{7}\cdot9,6-37,2=7\cdot9,6-37,2=67,2-37,2=30\).

\(\frac{c}{a}\cdot100\%=\frac{30}{60}\cdot100\%=50\%\).

Жауап: 1) 10%; 2) 50%.