a) (27 + 65) + (346 - 27 - 65) = 27 + 65 + 346 - 27 - 65
= 27 - 27 + 65 - 65 + 346 = 346.
b) (42 - 69 + 17) - (42 + 17) = 42 - 69 + 17 - 42 - 17
= 42 - 42 + 17 - 17 - 69 = -69.
a) (27 + 65) + (346 - 27 - 65)
= 27+65+346-27-65
= 27 + 65 +346 + (-27) + (-65)
= [27+(-27)] + [65+(-65)] + 346
= 0+0+346
=346
tk mik
hok tốt
a) \(\left(27+65\right)+\left(346-27-65\right)\)
\(=27+65+346-27-65\)
\(=\left(27-27\right)+\left(65-65\right)+346\)
\(=346\)
b) \(\left(42-69+17\right)-\left(42+17\right)\)
\(=42-69+17-42-17\)
\(=\left(42-42\right)+\left(17-17\right)-69\)
\(=-69\)
_Chúc bạn học tốt_
a) (27 + 65) + (346 - 27 - 65)
= 27 + 65 + 346 - 27 - 65
= (27 - 27) + (65 - 65) + 346
= 0 + 0 + 346 = 346
b) (42 - 69 + 17) - (42 + 17)
= 42 - 69 + 17 - 42 - 17
= (42 - 42) - 69 + (17 - 17)
= 0 - 69 + 0 = -69
b) (42 - 69 + 17) - (42 + 17).
=42-69+17-42-17
=42+(-69)+17+(-42)+(-17)
=[42+(-42)]+[17+(-17)]+(-69)
= 0+0+(-69)
=-69
tk mik nhé
a) =27+65+346-27-65=(27-27)+(65-65)+346=0+0+346=346
b) =42-69+17-42-17=(42-42)+(17-17)-69=0+0-69=69
