№ 4 ПОЖАЛУЙСТА!! И номер № 1!! И номер № 2!

4)Решение если только по действиям
$\frac{(3 \frac{3}{4}-5,1 ):( 3\frac{3}{4}+5,1 ) }{(1,4- \frac{2}{7} ):(1,4+ \frac{2}{7} )}=$ $- \frac{3}{13}$
1→ $3 \frac{3}{4}-5,1=3 \frac{3}{4}-5 \frac{1}{10}= \frac{15}{4} - \frac{51}{10}= \frac{75}{20} - \frac{102}{20}=- \frac{27}{20}$
2→ $3 \frac{3}{4}+5,1=3 \frac{3}{4}+5 \frac{1}{10}= \frac{15}{4} +\frac{51}{10}= \frac{75}{20} +\frac{102}{20}= \frac{177}{20}$
3→ $- \frac{27}{20}:\frac{177}{20}=- \frac{27}{20} * \frac{20}{177}=- \frac{27*20}{20*177}= -\frac{9}{59}$
4→ $(1,4- \frac{2}{7} )=1 \frac{4}{10}- \frac{2}{7}= \frac{14}{10}- \frac{2}{7}= \frac{7}{5}- \frac{2}{7}= \frac{49}{35}- \frac{10}{35}= \frac{39}{35}$
5→ $(1,4+\frac{2}{7} )=1 \frac{4}{10}+\frac{2}{7}= \frac{14}{10}+\frac{2}{7}= \frac{7}{5}+\frac{2}{7}= \frac{49}{35}+\frac{10}{35}= \frac{59}{35}$
6→ $\frac{39}{35}:\frac{59}{35}=\frac{39}{35}* \frac{35}{59}= \frac{39*35}{35*59}= \frac{39}{59}$
7→ $-\frac{9}{59}:\frac{39}{59}=-\frac{9}{59}* \frac{59}{39}=- \frac{9*59}{59*39}=- \frac{9}{39}=- \frac{3}{13}$