Question

Помогите срочно!!!!!!!!

Answer 1

Ответ:

$6)\ \ a=0,(63)\ \ ,\ \ \ \ 100a=63,(63)\\\\100a-a=63,(63)-0,(63)\\\\99a=63\ \ \to \ \ \ a=\dfrac{63}{99}\\\\\\b=1,(18)\ \ ,\ \ \ 100b=118,(18)\\\\100b-b=118,(18)-1,(18)\\\\99b=117\ \ \ \to \ \ \ b=\dfrac{117}{99}\\\\\\\dfrac{0,(63)}{1,(18)}\cdot 91=\dfrac{\dfrac{63}{99}\cdot 91}{\dfrac{117}{99}}=\dfrac{63\cdot 91}{117}=\boxed{49}$

$7)\ \ a=0,(18)\ \ ,\ \ \ 100a=18,(18)\\\\100a-a=18,(18)-0,(18)\\\\99a=18\ \ \ \to \ \ \ a=\dfrac{18}{99}\\\\\\b=1,(72)\ \ \ ,\ \ \ 100b=172,(72)\\\\100b-b=172,(72)-1,(72)\\\\99b=171\ \ \ \to \ \ \ b=\dfrac{171}{99}\\\\\\\dfrac{0,(18)+1,(72)}{21}\cdot 330=\dfrac{\dfrac{18}{99}+\dfrac{171}{99}}{21}\cdot 330=\dfrac{189\cdot 330}{99\cdot 21}=\boxed{30}$