№1 (0,4-11/15)умножить 1 2/7-(7/18 -0,5): 1 1/6 №2 (- 3/5 умножить 0,8 - 13/25) умножить 0,7 №3 (-2,6)2 в квадрате - (-3,2) умножить(-3/8)+(-6,56) если возможно объясните как решили

Ответ:

Fleepee

08.07.2020 01:43

№1
$(0,4-\frac{11}{15})*1\frac{2}{7}-(\frac{7}{18}-0,5):1\frac{1}{6}= \\ \\ =(\frac{4}{10}-\frac{11}{15})*1\frac{2}{7}-(\frac{7}{18}-\frac{5}{10}):1\frac{1}{6}= \\ \\ =(\frac{2}{5}-\frac{11}{15})*1\frac{2}{7}-(\frac{7}{18}-\frac{1}{2}):1\frac{1}{6}$

$\frac{2}{5}-\frac{11}{15}=\frac{3*2-11}{15}=\frac{-5}{15}=-\frac{1}{3} \\ \\ \frac{7}{18}-\frac{1}{2}=\frac{7-9*1}{18}=\frac{-2}{18}=-\frac{1}{9} \\ \\ -\frac{1}{3}*1\frac{2}{7}=-\frac{1}{3}*\frac{7*1+2}{7}=-\frac{1}{3}*\frac{9}{7}=-\frac{3}{7} \\ \\ -\frac{1}{9}:1\frac{1}{6}=-\frac{1}{9}:\frac{6*1+1}{6}=-\frac{1}{9}:\frac{7}{6}=-\frac{1}{9}*\frac{6}{7}=-\frac{1}{3}*\frac{2}{7}=-\frac{2}{21}$

$-\frac{3}{7}-(-\frac{2}{21})=-\frac{3}{7}+\frac{2}{21}=\frac{2}{21}-\frac{3}{7}=\frac{2-3*3}{21}=-\frac{7}{21}=-\frac{1}{3}$

№2
$(-\frac{3}{5}*0,8-\frac{13}{25})*0,7=(-\frac{3}{5}*\frac{8}{10}-\frac{13}{25})*\frac{7}{10}=(-\frac{3}{5}*\frac{4}{5}-\frac{13}{25})*\frac{7}{10} \\ \\ -\frac{3}{5}*\frac{4}{5}=-\frac{3*4}{5*5}=-\frac{12}{25} \\ \\ -\frac{12}{25}-\frac{13}{25}=\frac{-12-13}{25}=-\frac{25}{25}=-1 \\ \\ -1*\frac{7}{10}=-\frac{7}{10}$

№3
$(-2,6)^2-(-3,2)*(-\frac{3}{8})+(-6,56)= \\ \\ (-\frac{26}{10})^2-(-\frac{32}{10})*(-\frac{3}{8})+(-\frac{656}{100})=\frac{676}{100}-(-\frac{16}{5})*(-\frac{3}{8})+(-\frac{656}{100}) \\ \\ (-\frac{16}{5})*(-\frac{3}{8})=\frac{(-16)*(-3)}{5*8}=\frac{48}{40}=\frac{6}{5} \\ \\ \frac{676}{100}-\frac{6}{5}=\frac{676-20*6}{100}=\frac{676-120}{100}=\frac{556}{100} \\ \\ \frac{556}{100}+(-\frac{656}{100})=\frac{556}{100}-\frac{656}{100}=\frac{556-656}{100}=-\frac{100}{100}=-1$