Question

помогите с этими задачками​

Answer 1

Ответ:

6)

$1)\frac{4}{7}* \frac{7}{7}- \frac{3}{7}= \frac{4}{7}* 1- \frac{3}{7}=\frac{4}{7}- \frac{3}{7}=\frac{1}{7} \\\\2)\frac{12}{28}* \frac{11}{28}+\frac{9}{28}=\frac{3}{7}* \frac{11}{28}+ \frac{9}{28}=\frac{33}{196}+ \frac{9}{28}=\frac{33}{196}+ \frac{63}{196}=\frac{96}{196}=\frac{24}{49} \\\\3)\frac{5}{9}+\frac{2}{9} *\frac{1}{9}+\frac{4}{9}=\frac{5}{9}+ \frac{2}{81}+\frac{4}{9}=\frac{5}{9} +\frac{4}{9} +\frac{2}{81}=1+\frac{2}{81}=1\frac{2}{81}$

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7)

$\frac{8}{100}+x=\frac{34}{100}+ \frac{56}{100} \\\\ \frac{8}{100}+x=\frac{90}{100}\\\\x=\frac{90}{100}- \frac{8}{100} \\\\x=\frac{82}{100} \\\\x=\frac{41}{50}$

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$\frac{60}{90}-(\frac{6}{90}+x)=\frac{29}{90} \\\\ \frac{60}{90}-\frac{6}{90}-x=\frac{29}{90} \\\\\frac{54}{90}-x=\frac{29}{90}\\\\-x=\frac{29}{90}- \frac{54}{90}\\\\-x= -\frac{25}{90} \\\\x=\frac{25}{90} \\\\x=\frac{5}{18}$

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10)

$\frac{67}{90}-\frac{50}{90} +\frac{2}{90}=\frac{17}{90}+ \frac{2}{90}=\frac{19}{90}$

$\frac{23}{30}+\frac{5}{30} -\frac{19}{30}=\frac{28}{30}- \frac{19}{30}=\frac{9}{30}$

Пошаговое объяснение: