Đáp án + Giải thích các bước giải:
Bài `1` :
`a, 5 . 5 . 5 . 5 . 5 . 5`
`= 5^6`
`b, 2 . 2 . 2 . 2 . 3 . 3 . 3 . 3`
`= 2^4 . 3^4`
`c, 100 . 10 . 2 . 5`
`= 10 . 10 . 10 . 10`
`= 10^4`
`d, 3 . 3^4 . 3^5`
`= 3^5 . 3^5`
`= 3^5+5`
`= 3^10`
`e, 7^3 : 7^2 : 7`
`= 7^3-2 : 7`
`= 7^1 : 7`
`= 7 : 7`
`= 1`
`f, (x^4)^3`
`= x^4.3`
`= x^12`
`g, (2^4)^2`
`= 2^4.2`
`= 2^8`
Bài `2` :
`a, 5 . 2^2 - 18 : 3`
`= 5 . 4 - 6`
`= 20 - 6`
`= 14`
`b, 17 . 85 + 15 . 17 - 2^3 . 3 . 5`
`= 17 . ( 85 + 15 ) - 8 . 3 . 5`
`= 17 . 100 - 24 . 5`
`= 1700 - 120`
`= 1580`
`c, 2^3 . 17 - 2^3 . 14`
`= 2^3 . ( 17 - 14 )`
`= 8 . 3`
`= 24`
`d, 20 - [30 - ( 5 - 1 )^2]`
`= 20 - [30 - 4^2 ]`
`= 20 - [ 30 - 16 ]`
`= 20 - 14`
`= 6`
`e, 75 - (3 . 5^2 - 4 . 2^3)`
`= 75 - ( 3 . 25 - 4 . 8 )`
`= 75 - ( 75 - 32 )`
`= 75 - 43`
`= 32`
`f, 2 . 5^2 + 3 : 71^0 - 54 : 3^3`
`= 2. 25 + 3 : 1 - 54 : 27`
`= 50 + 3 - 2`
`= 53 - 2`
`= 51`
`g, 150 + 50 : 5 - 2 . 3^2`
`= 150 + 25 - 2 . 9`
`= 175 - 18`
`= 157`
`h, 5 . 3^2 - 32 : 4^2`
`= 5 . 9 - 32 : 16`
`= 45 - 2`
`= 43`
Bài `3` :
`540 + ( 345 - x ) = 740`
`(345 - x ) = 740 - 540`
`345 - x = 200`
`x = 345 - 200`
`x = 145`
Bài `4` :
`928 - ( 31+ x ) = 128`
`( 31 + x ) = 928 - 128`
` 31 + x = 800`
`x = 800 - 31`
`x = 769`
