`1`
`a ) 2023 - 25^2 : 5^3 + 27`
`= 2023 - 5^4 : 5^3 + 27`
`= 2023 - 5^1 + 27`
`= 2023 - 5 + 27`
`= 2018 + 27`
`= 2045`
`b ) 60 : [7 . (11^2 - 20 . 6) + 5]`
`= 60 : [7 . ( 121 - 120 ) + 5]`
`= 60 : [7 . 1 + 5]`
`= 60 : [7 + 5]`
`= 60 : 12`
`= 5`
`2`
`a ) (9x - 2^3 ) : 5 = 2`
`9x - 8= 2 . 5`
`9x - 8= 10`
`9x = 10 + 8`
`9x = 18`
`x = 18 : 9`
`x = 2`
Vậy `x = 2`
`b ) [3^4 - ( 8^2 + 14 ) : 13]x = 5^3 + 10^2`
`[81 - ( 64 + 14 ) : 13]x = 125 + 100`
`[81 - 78 : 13]x = 225`
`[81 - 6]x = 225`
`75x = 225`
`x = 225 : 75`
`x = 3`
Vậy `x = 3`
`3`
`a ) 2027^2 - 1973^2 = 216000`
`b ) 4^2 + ( 365 - 289 ) . 71 = 5412`
`#dtkc`