Bài 2: Bỏ dấu ngoặc rồi tính:
1) (15 + 37) + (52 – 37 – 17) 2) (38 – 42 + 14) – (25 – 27 – 15) 3) –(21 – 32) – (–12 + 32)
=50 =10-(-170 =-(-11)-20
=27 =-9
4) –(12 + 21 – 23) – (23 – 21 + 10) 6) (55 + 45 + 15) – (15 - 55 + 45) 7)(35 + 75) + (345 – 35 -75)
=-10-12 =115-5 =110+235
=-22 =110 =345
5) (57 - 725) - (605 – 53) 8) (2002 – 79 + 15) – (-79 + 15) 9)– (515 – 80 + 91) – (2003 + 80 - 91)
=-668-552 =1938-64 =-526-1992
=-1220 =1874 =-2518
10) 25 – (–17) + 24 – 12 11) 235 – (34 + 135) –100 12/ ( 13 + 49) – ( 13 – 135 + 49)
=54 =135-169-100=-134 =62-73=-11
13/ ( 18 + 29) + ( 158 – 18 – 29)
=47+111=158
CHÚC BẠN HỌC TỐT!!!