i water the trees twice a day 

how often do you feed the cat?

my father took me to the zoo yesterday.

when đi they build the imperial acdemy 

hoa did not do her homework

mai does not usually sweep the house

chuyển sang bị động hộ mik ah

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) – 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)  

 20/