a 3/5 + - 7/4 b (-2) + - 5/8 c 1 /-8 + -5/9 d 6/13 + -14/39 giúp mink với vote 5 sao

a) $\frac{3}{5}$ + $\frac{-7}{4}$ 

= $\frac{12}{20}$ + $\frac{-35}{20}$ 

= $\frac{12 + (-35)}{20}$ = $\frac{-23}{20}$ 

b) (-2) + $\frac{5}{8}$ 

= $\frac{-16}{8}$  + $\frac{5}{8}$ 

= $\frac{-16 + 5 }{8}$ = $\frac{-11}{8}$ 

c) $\frac{1}{-8}$ + $\frac{-5}{9}$ 

= $\frac{-1}{8}$ + $\frac{-5}{9}$ 

= $\frac{-9}{72}$ + $\frac{-40}{72}$ 

=  $\frac{-9 + (-40)}{72}$ = $\frac{-49}{72}$ 

d) $\frac{6}{13}$ + $\frac{-14}{39}$ 

= $\frac{18}{39}$ + $\frac{-14}{39}$ 

= $\frac{18+(-14)}{39}$ = $\frac{4}{39}$ 

# hung6atptt

# cho mình xin câu trả lời hay nhất 

$ leduyhien7020 $

` a) 3/5 + (-7)/4 `

` = 12/20 + (-35)/20 `

` = (-23)/20 `

` b) (-2) + (-5)/8 `

` = -(2+5/8) `

` = -(16/8+5/8) `

` = -21/8 `

` c) 1/-8 + (-5)/9 `

` = (-9)/72 + (-40)/72 `

` = (-49)/72 `

` d) 6/13 + (-14)/39 `

` = 18/39 + (-14)/39 `

` = 4/39 `