Thực hiện phép tính

Bài 1.2: Thực hiện phép tính (Tính hợp lí nếu có thể)

1/  (-30) + 15 + 10 + ( -15)   ;                            

 2/   17 + ( -12) + 25 –  17 ;

3/   – (-219) + (-219) – 401 + 12

4/    4567 + (1234 – 4567) -4

5/   (3567 – 214) – 3567;                                 

6/ (-2017) – (28 – 2017);

7/   - (269 – 357) + (269 – 357);              

8/. 2001 – (53 + 1579) – (-53)

9/. 35 – 17 + 2017 – 35 + (-2017)

10/. 37 + (-17) – 37 + 77

11/   ( 123 + 345) + (456 – 123) –<!--[if gte vml 1]> <!--[endif]--><!--[if gte mso 9]--><xml> </xml><![endif]-->

12/   ( 17 – 229) + ( 17 - 25 + 229) ;                  

13/ ( 125 – 679 + 145) – ( 125 – 679 )  

14/   17. (15 – 16) + 16. (17 – 20)

15/   15. (-176) + 15.76 + 100.15

16/   79.89 – 79. (-11) – 100.79

17/    153.177 – 153.77 + 100. (-77)

18/ (-29). (85 – 47) – 85. (47 – 29)

19/ (-167). (67 – 34) – 67. (34 – 167)  

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