Bài `44:`
`a)`
`25^3 : 5^2`
`= (5^2)^3 : 5^2`
`= 5^6 : 5^2`
`= 5^4`
`b)`
`(3/7)^21 : (9/49)^6`
`= (3/7)^21 : [(3/7)^2]^6`
`= (3/7)^21 : (3/7)^12`
` = (3/7)^9`
`c)`
`3 - (-6/7)^0 + (1/2)^2 : 2`
`= 3 - 1 + 1/4 : 2`
` = 2 + 1/8`
`= 17/8`
Bài `45:`
`a)`
` 9 . 3^3 . 1/81 . 3^2`
` = 3^2 . 3^3 . 3^2 . 1/81`
` = 3^7 . 1/81`
` = (3^7)/81`
` = (3^7)/(3^4)`
` = 3^3 `
`b)`
`4 . 2^5 : ( 2^3 . 1/16)`
` = 2^2 . 2^5 : (8 . 1/16)`
` = 2^7 : 1/2`
`= 2^7 . 2`
` = 2^8`
`c)`
`3^2 . 2^5 . (2/3)^2`
`= (3 . 2/3)^2 . 2^5`
`= 2^2 . 2^5`
` = 2^7`
`d)`
`(1/3)^2 . 1/3 . 9^2`
` = (1/3 . 9)^2 . 1/3`
`= 3^2 . 1/3`
` = (3^2)/3`
` = 3`
