a) 12 - (8 . 22 - 4 . 23)
= 12 - (4 . 2 . 22 - 4 . 23)
= 12 - (4 . 23 - 4 . 23)
= 12 - 0
= 12
b) 56 : 54 + 22 . 23
= 52 + 25
= 25 + 32
= 57
c) 28 . 76 + 35 . 28 - 11 . 28
= 28 (76 + 35 - 28)
= 28 .100
= 2800
d) 3. 42 - 62 :2
= 3. 16 - 36 :2
= 48 - 18
= 30
e) 13 . 42 + 13 . 58 - 50 : (32 + 42)
= 13 . 42 + 13 . 58 - 50 : (9+ 16)
= 13 . (42 + 58) - 50 : (9+ 16)
= 13 .100 - 50 : 25
= 1300 - 2
= 1298
g) 34 : 32 + 2 . 23
= 32 + 24
= 9 + 16
= 25
HỌC TỐT