2 câu trả lời
`\frac{-5}{-15}+\frac{9}{7}+\frac{1}{-3}-(-\frac{276}{14})`
`=\frac{1}{3}+\frac{9}{7}-\frac{1}{3}+\frac{276}{14}`
`=(\frac{1}{3}-\frac{1}{3})+(\frac{9}{7}+\frac{276}{14})`
`=\frac{18}{14}+\frac{276}{14}`
`=\frac{294}{14}`
`=21`
`(-5)/(-15)+9/7+1/(-3)-(-276/14)`
`=1/3+ 9/7+ (-1)/3 + 138/7`
`=(1/3+(-1)/3)+(9/7+138/7)`
`= 0 + 21`
`=21`