Question

Помогите решить: (/-это дробь)
(3 3/8∙4/9+9,54)/(5,1-2,8)

4,2/25,2

2 2/5)/(1 1/5)

(4 2/7∙1 3/4-3,36)/(0,8+1,5)

-21/8 -15/16

-( 7)/9+5/6

Answer 1

1) $frac{3 frac{3}{8}* frac{4}{9} +9,54}{5,1-2,8} = frac{ frac{27}{8}* frac{4}{9}+9,54 }{2,3} = frac{ frac{27*4}{8*9} +9,54}{2,3} = frac{1,5+9,54}{2,3} = frac{11,04}{2,3} = frac{ frac{1104}{100} }{ frac{23}{10} }= frac{1104}{100}* frac{10}{23} = frac{1104*100}{100*23} = frac{48}{10} =4,8$
2) $frac{4,2}{25,2} = frac{ frac{42}{10} }{ frac{252}{10} } = frac{42}{10} * frac{10}{252}= frac{42*10}{10*252} = frac{42}{252} = frac{1}{6}$
3) $frac{2 frac{2}{5} }{1 frac{1}{5} } = frac{12}{5}* frac{5}{6} = frac{12*5}{5*6} = 2$
4) $frac{ 4frac{2}{7}*1 frac{3}{4} -3,36 }{0,8+1,5} = frac{ frac{30}{7}* frac{7}{4} -3,36 }{2,3} = frac{ frac{30*7}{7*4}-3,36 }{2,3} = frac{ frac{30}{4} -3,36}{2,3} = frac{7,5-3,36}{2,3} = frac{4,14}{2,3} = frac{ frac{414}{100} }{ frac{23}{10}}=frac{414}{100} * frac{10}{23} = frac{414*10}{100*23} = frac{18}{10} =1,8$
5) $- frac{21}{8} - frac{15}{16}=- frac{21*2+15}{16} = -frac{42+15}{16} = -frac{57}{16} =-3 frac{9}{16}$
6) $- frac{7}{9} + frac{5}{6} = frac{(-7)*4+5*6}{36} = frac{-28+30}{36}= frac{2}{36}= frac{1}{18}$