Question

[concholonnay]

Giúp mình với thứ 5 cô giáo kt

a \(\frac{1}{7}\)x \(\frac{1}{3}\)+ \(\frac{1}{7}\)x \(\frac{1}{2}\)- \(\frac{1}{7}\)

b 21 ( \(\frac{1}{7}\)- \(\frac{1}{5}\)+ \(\frac{19}{21}\))

c  { \(\frac{1}{3}\)( \(\frac{6}{5}\)- \(\frac{9}{4}\)) - \(\frac{7}{5}\)( \(\frac{15}{14}\)+ \(\frac{5}{7}\)) } : ( \(\frac{1}{2}\)- \(\frac{1}{3}\)+ \(\frac{5}{6}\))

MÌNH CẦN GẤP AI TRẢ LỜI NHANH VÀ ĐÚNG MIK TICK CHO

Answer 1

[%Hz@]

a)\(\frac{1}{7}.\frac{1}{3}+\frac{1}{7}.\frac{1}{2}-\frac{1}{7}\)

\(=\frac{1}{7}.\left(\frac{1}{3}+\frac{1}{2}\right)-\frac{1}{7}\)

\(=\frac{1}{7}.\left(\frac{2}{6}+\frac{3}{6}\right)-\frac{1}{7}\)

\(=\frac{1}{7}.\frac{5}{6}-\frac{1}{7}\)

\(=\frac{5}{42}-\frac{1}{7}\)

\(=\frac{5}{42}-\frac{6}{42}=-\frac{1}{42}\)