Bài 1:
a, ( $\frac{4}{9}$+ $\frac{5}{6}$) : ($\frac{7}{8}$- $\frac{7}{12}$)
b, ($\frac{5}{8}$ + $\frac{4}{15}$). (2- $\frac{2}{107}$
Bài 2:
a, 2$\frac{3}{13}$ :(-$\frac{1}{8}$)+5 $\frac{10}{13}$ :(- $\frac{1}{8}$
Bài 1:
a, ( $\frac{4}{9}$+ $\frac{5}{6}$) : ($\frac{7}{8}$- $\frac{7}{12}$)
b, ($\frac{5}{8}$ + $\frac{4}{15}$). (2- $\frac{2}{107}$
Bài 2:
a, 2$\frac{3}{13}$ :(-$\frac{1}{8}$)+5 $\frac{10}{13}$ :(- $\frac{1}{8}$
Lời giải:
Bài 1:
a) $(\frac{4}{9}+\frac{5}{6}):(\frac{7}{8}-\frac{7}{12})$
$=(\frac{8}{18}+\frac{15}{18}):(\frac{21}{24}-\frac{14}{24})$
$=\frac{23}{18}:\frac{7}{24}$
$= \frac{23}{18}.\frac{24}{7}$
$= \frac{92}{21}$
b) $(\frac{5}{8}+\frac{4}{15}).(2-\frac{2}{107})$
$=(\frac{75}{120}+\frac{32}{120}).(\frac{214}{107}-\frac{2}{107})$
$=\frac{107}{120}.\frac{212}{107}$
$= \frac{107.53.4}{30.4.107}$
$= \frac{53}{30}$
Bài 2:
a) $2\frac{3}{13}:(-\frac{1}{8})+5\frac{10}{13}:(-\frac{1}{8})$
$= \frac{29}{13}:(-\frac{1}{8})+\frac{75}{13}:(-\frac{1}{8})$
$=(\frac{29}{13}+\frac{75}{13}):(-\frac{1}{8})$
$= \frac{104}{13}. (-8)$
$=64$
Đáp án:
Giải thích các bước giải:
1.
` ( 4/9 + 5/6 ) : ( 7/8 – 7/12 ) `
` = 23/18 : 7/24 `
` =92/21 `
`( 5/8 + 4/15 ) . ( 2 – 2/107) `
`=107/120 . 212/107 `
` = 53/30 `
2.
` \frac{3}{13}:(-\frac{1}{8})+5\frac{10}{13}:(-\frac{1}{8}) `
` = \frac{29}{13}:(-\frac{1}{8})+\frac{75}{13}:(-\frac{1}{8}) `
`=(\frac{29}{13}+\frac{75}{13}):(-\frac{1}{8})`
`= \frac{104}{13}. (-8)`
`=64`