Tính các tổng sau :
a, [25+(-15)] + (-29)
b, 512 -(-88) – 400 – 125
c, -(-310) + (-210) – 907 + 107
d, 2004- (1975) – (2000) + 2005
Tính các tổng sau : a, [25+(-15)] + (-29) b, 512 -(-88) – 400 – 125 c, -(-310) + (-210) – 907 + 107 d, 2004- (1975) – (2000) + 2005
By Caroline
a, [25+(-15)]+(-29)
=10-29
=-19
b, 512 -(-88) – 400 – 125
=512+88-400-125
=(512+88)-400-125
=600-400-125
=200-125
=75
c, -(-310) + (-210) – 907 + 107
=310-210-907+107
=(310-210)+(-907+107)
=100-800
=-700
d, 2004- (1975) – (2000) + 2005
=2004-1975-2000+2005
=(2004-2000)+2005-1975
=4+2005-1975
=2009-1975
=34
a. [25+(-15)] + (-29)
= 25 – 15 -29
= 10 – 29
= -19
b. 512 -(-88) – 400 – 125
= 512 + 88 – 400 – 125
= 600 – 400 – 125
= 200 – 125
= 75
c. -(-310) + (-210) – 907 + 107
= 310 – 210 – 907 + 107
= (310- 210) + (-907 + 107)
= 100 + (-800)
= 100 – 800
= -700
d. 2004- (1975) – (2000) + 2005
= 2004 – 1975 – 2000 + 2005
= (2004-2000) + (-1975 + 2005)
= 4 + 30
= 34