Tính bằng cách hợp lí nhất a) 453.(−27) + 27.353. b) 34.(66 − 5) − 66.(34 + 5)
Giải thích
1. 453.(−27) + 27.353
= 27.(−453 + 353)
= 27.(−100)
= −2700.
2. 34.(66 − 5) − 66.(34 + 5)
= 34.66 − 34.5 − 66.34 − 66.5
= −5.(34 + 66)
= −500.
1. 453.(−27) + 27.353
= 27.(−453 + 353)
= 27.(−100)
= −2700.
2. 34.(66 − 5) − 66.(34 + 5)
= 34.66 − 34.5 − 66.34 − 66.5
= −5.(34 + 66)
= −500.