A.( 13 + 25 ) + ( 24 - 13 - 42 - 25 )

= 13 + 25 + 24 - 13 - 42 - 25

= ( 13 - 13 ) + ( 25 - 25 ) + ( 24 - 42 )

= 0 + 0 + ( - 18 )

= -18

B. ( 215 - 34 + 127 ) - ( 315 - 144 - 227 )

= 215 - 34 + 127 - 315 + 144 + 227

= ( 215 - 315 ) + ( 144 - 34 ) + ( 127 + 227 )

= - 100 + 110 + 354

= 10 + 354

= 364

cọu lên gg í <<:

??????????!

a) (–37 ) + (–112)

= –(37 + 112) (cộng hai số nguyên âm).

= –149.

b) (–42) + 52

= 52 – 42 (cộng hai số nguyên khác dấu)

= 10

c) 13 – 31 = –31 + 13 = – (31 – 13) = –18.

d) 14 – 24 – 12 = 14 – (24 + 12) = 14 – 36 = – (36 – 14) = –22.

e) (–25) + 30 – 15 = 30 – 25 – 15 = 30 – (25 + 15) = 30 – 40 = –10

(-25)-(-12)= - 13

18+(14-42)=18+(-28) = -10

(-18)-13+17=(-31) +17= -14

\(\rightarrow\)-13 < -10 > -14\(\Rightarrow\) (-25)-(-12) < 18+(14-42) > (-18)-13+17

5/14x7/13x26/25
Bạn để ý rút gọn 14 cho 7 như sau
5/2x1/13x26/25
=5/26x26/25
Rút gọn 26 với 26,ta đc 5/25=1/5

\(\frac{5}{14}\times\frac{7}{13}\times\frac{26}{25}\)\(=\frac{5\times7\times13\times2}{7\times2\times13\times5\times5}\)\(=\frac{1}{5}\)

ta có phép tính:\(\frac{5}{14}\)x\(\frac{7}{13}\)x\(\frac{26}{25}\)=\(\frac{5x7x26}{14x13x25}\)=\(\frac{910}{4550}\)=\(\frac{91}{455}\)

= 70 

tk

cho 

mik

= 75 + 25 - 13 - 17

= (75 + 25) - (13 + 17)

= 100 - 30

= 70

l​m the nao