`(-3/7) .5/11 + 3/14 . 2/5`
`= -15/77 + 3/35`
`= -150/770 + 66/770`
`= -84/770`
`=-6/55`
`0,(6) + 1,(6) `
`= 2/3 +5/3`
`=7/3`
`3,(6) + 1,(36) . 2 1/5`
`= 3,(6) + 1,(36) . 11/5`
`= 3,(6) + 15/11 . 11/5`
`= 3,(6) + 3`
`= 6,(6)`
\(a,\left(-\dfrac{3}{7}\right).\dfrac{5}{11}+\dfrac{3}{14}.\dfrac{2}{5}\)
\(=\left(-\dfrac{3}{7}\right).\dfrac{5}{11}+\dfrac{3}{7}.\dfrac{1}{5}\)
\(=\dfrac{3}{7}.\left(-\dfrac{5}{11}\right)+\dfrac{3}{7}.\dfrac{1}{5}\)
\(=\dfrac{3}{7}.\left[\left(-\dfrac{5}{11}\right)+\dfrac{1}{5}\right]\)
\(=\dfrac{3}{7}.\left[\left(-\dfrac{25}{55}\right)+\dfrac{11}{55}\right]\)
\(=\dfrac{3}{7}.-\dfrac{14}{55}\)
\(=\dfrac{3}{1}.-\dfrac{2}{55}\)
\(=-\dfrac{6}{55}\)
b) \(0,\left(6\right)+1,\left(6\right)\)
= \(\dfrac{2}{3}+\dfrac{5}{3}\)
\(=\dfrac{7}{3}\)
c) \(3,\left(6\right)+1,\left(36\right).2\dfrac{1}{5}\)
\(=\dfrac{11}{3}+\dfrac{15}{11}.\dfrac{11}{5}\)
\(=\dfrac{11}{3}+\dfrac{3.1}{1.1}\)
\(=\dfrac{11}{3}+3\)
\(=\dfrac{11}{3}+\dfrac{9}{3}\)
\(=\dfrac{20}{3}\)
\(b,0,\left(6\right)+1,\left(6\right)\)
\(=0+6\)
\(=6\)
\(c,3,\left(6\right)+1,\left(36\right).2\dfrac{1}{5}\)
\(=18+36.\dfrac{11}{5}\)
\(=18+\dfrac{396}{5}\)
\(=\dfrac{486}{5}\)
\(b,0,\left(6\right)+1, \left(6\right)\)
\(=\dfrac{2}{3}+\dfrac{5}{3}\)
\(=\dfrac{7}{3}\)
\(,3,\left(6\right)+1,\left(36\right).2\dfrac{1}{5}\)
\(=\dfrac{11}{3}+\dfrac{15}{11}.\dfrac{11}{5}\)
\(=\dfrac{11}{3}+3\)
\(=\dfrac{20}{3}\)
(đã sửa)
