Đáp án:
Câu 1:
a) `-\frac{11}{14}` + `\frac{4}{7}` + `\frac{1}{2}`
= `-\frac{11}{14}` + `\frac{8}{14}` + `\frac{7}{14}`
= `\frac{2}{7}`
b) `-\frac{8}{20}` `+` `0,9` . `(``\frac{1}{3}` `-` `\frac{1}{5}``)``:``20%`
= `-\frac{2}{5}` `+` `\frac{9}{10}` . `(``\frac{1}{3}` `-` `\frac{1}{5}``)``:``\frac{1}{5}`
= `-\frac{2}{5}` `+` `\frac{9}{10}` . `\frac{2}{15}``:``\frac{1}{5}`
= `-\frac{2}{5}` `+` `\frac{3}{25}``:``\frac{1}{5}`
= `-\frac{2}{5}` `+` `\frac{3}{5}`
= `\frac{1}{5}`
Cau 2:
a) `\frac{1}{3}` `+` `\frac{1}{3}` : `x` = `-\frac{1}{5}`
`\frac{1}{3}` : `x` = `-\frac{1}{5}` `-` `\frac{1}{3}`
`\frac{1}{3}` : `x` = `-\frac{8}{15}`
`x` = `\frac{1}{3}` :`-\frac{8}{15}`
`x` = `-\frac{5}{8}`
Vậy `x` = `-\frac{5}{8}`
b) `x` `-``\frac{1}{3}` .`x` = `2\frac{1}{3}`
`x`.`(``1``-``\frac{1}{3}``)` = `\frac{7}{3}`
`x`.`\frac{2}{3}` = `\frac{7}{3}`
`x` = `\frac{7}{3}`:`\frac{2}{3}`
`x` = `\frac{7}{2}`
Vậy `x` = `\frac{7}{2}`
#Jen_
