Esatto pagina 32 n 136

136)

$1,5×0,\overline{18}×1,\overline6-\dfrac{4}{11}=$

$= \dfrac{15}{10}×\dfrac{18-0}{99}×\dfrac{16-1}{9}-\dfrac{4}{11}=$

$= \dfrac{\cancel{15}^3}{\cancel{10}_2}×\dfrac{18}{99}×\dfrac{15}{9}-\dfrac{4}{11}=$

$= \dfrac{3}{2}×\dfrac{\cancel{18}^2}{\cancel{99}_{11}}×\dfrac{\cancel{15}^5}{\cancel{9}_3}-\dfrac{4}{11}=$

$= \dfrac{3}{2}×\dfrac{2}{11}×\dfrac{5}{3}-\dfrac{4}{11}=$

$= \dfrac{\cancel3^1}{\cancel2_1}×\dfrac{\cancel2^1}{11}×\dfrac{5}{\cancel3_1}-\dfrac{4}{11}=$

$= \dfrac{1}{1}×\dfrac{1}{11}×\dfrac{5}{1}-\dfrac{4}{11}=$

$= \dfrac{5}{11}-\dfrac{4}{11}=$

$= \dfrac{1}{11}$

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$0,\overline5×7,5 : 0,8\overline3 =$

$= \dfrac{5-0}{9}×\dfrac{75}{10} : \dfrac{83-8}{90} =$

$= \dfrac{5}{9}×\dfrac{\cancel{75}^{15}}{\cancel{10}_2} : \dfrac{75}{90}=$

$= \dfrac{5}{9}×\dfrac{15}{2} : \dfrac{\cancel{75}^5}{\cancel{90}_6}=$

$= \dfrac{5}{\cancel9_3}×\dfrac{\cancel{15}^5}{2} : \dfrac{5}{6}=$

$= \dfrac{5}{3}×\dfrac{5}{2} × \dfrac{6}{5}=$

$= \dfrac{5}{3}×\dfrac{\cancel5^1}{\cancel2_1} × \dfrac{\cancel6^3}{\cancel5_1}=$

$= \dfrac{5}{3}×\dfrac{1}{1} × \dfrac{3}{1}=$

$= \dfrac{5}{3}×\dfrac{3}{1}=$

$= \dfrac{5}{\cancel3_1}×\dfrac{\cancel3^1}{1}=$

$= \dfrac{5}{1}×\dfrac{1}{1}=$

$= 5$