Đáp án:
a) `-5 + (-11)`
`= -(5 + 11)`
`= -16`
b) `21 - 34`
`= -(34 - 21)`
`= -13`
c) `16 - 6 × 3`
`= 16 - 18`
`= -2
d) `\frac{7}{5} - \frac{2}{5}`
`= \frac{7-2}{5}`
`= 1`
e) `\frac{3}{7} - \frac{17}{7}`
`= \frac{3-17}{7}`
`= -2`
f) `\frac{3}{4} - \frac{2}{3}`
`= \frac{9}{12} - \frac{8}{12}`
`= \frac{1}{12}`
Chúc học tốt!!!