Помогите 984 985 дам 98 баллов!!

Ответ:

Пошаговое объяснение:

$1) 1,(8) = 1\dfrac{8}{9} \\\\2) 0,(3)=\dfrac{3}{9} =\dfrac{1}{3} \\\\3)0,(7)=\dfrac{7}{9} \\\\4)3,(5)=3\dfrac{5}{9} \\\\5)0,1(2)=\dfrac{12-1}{90} =\dfrac{11}{90} \\\\6)1,12(3)=1\dfrac{123-12}{900} =1\dfrac{111}{900} =1\dfrac{37}{300} \\\\7)7,5(4)=7\dfrac{54-5}{90} =1\dfrac{49}{90} \\\\8)0,(35)=\dfrac{35}{99} \\\\9)0,(59)=\dfrac{59}{99}\\\\ 10)0,(12)=\dfrac{12}{99} =\dfrac{4}{33} \\\\11)1,0(12)=1\dfrac{12}{990} =1\dfrac{4}{330}\\\\ 12)8,7(21)=8\dfrac{721-7}{990}=8\dfrac{119}{165}$

$2.\\0,3(9) = a\\\\10a = 3,(9) = 3,6 + 0,3(9) = 3,6 + a\\9a = 3,6\\a = 0,4$

$1,2(9)=a\\\\10a = 12,(9) = 11,7 + 1,2(9) =11,7+a\\9a = 11,7\\a = 1,3$