2 câu trả lời
`2/7 + 5/7 (3/5 - 1/4) . (-2^2) + 7/20`
`= 2/7 + 5/7 . 7/20 . (-4) + 7/20`
`= 2/7 + 1/4 . (-4) +7/20`
`= 2/7 + (-1) + 7/20`
`= (-5)/7 + 7/20`
`= (-51)/140`
`#dtkc`
`2/7` `+` `5/7` `(``3/5` `-` `1/4``) * - 2` mũ `2 +` `7/20` `=>` `-0,3642`