câu 1 :
a ) 27 : 9 + 3.2 - 8 = 3 + 6 - 8 = 9 - 8 = 1
b ) 2020 mũ 2021 : 2020 mũ 2020 - [ 27 - 56 : 8 ] . 5 = 2020 mũ 2021 : 2020 mũ 2020 - [ 27 - 7 ] . 5= 2020 - 20 . 5 = 2020 - 100 = 1920
c) 123 . ( 16 + 25 + 41 ) = 123 . 82 = 10086
câu 2
a) 45 : x + 36 = 41 b) 25 + 17 . x = 4 .16 c
45: x = 41-36 25 + 17 . x = 64
x = 45 : 5 17 . x = 64 - 25
x = 9 x = 39 : 17
x = 2,9