`a) A = ((-2)/3 + 1/2) : 4/3 + ((-1)/4 + 2/5) . 10/3`
`= (-1)/6 . 3/4 + 3/20 . 10/3`
`= (-1)/8 + 4/8`
`= 3/8`
`b) B = 5/8 . (1/3 - 4/5) + 5/8 . (2/3 + 1/5)`
`= 5/8 . (1/3 - 4/5 +2/3 + 1/5)`
`= 5/8 . [(1/3 +2/3) + (1/5 - 4/5)]`
`= 5/8 . (1 + (-1))`
`= 5/8 . 0`
`= 0`
`c) C = (-2,5 . 0,38 . 0,4) - [0,125 . 3,15 . (-8)]`
`= (-2,5 . 0,4. 0,38) - [0,125 . (-8). 3,15]`
`= (-1. 0,38) - (-1. 3,15)`
`= (-0,38) - (-3,15)`
`= (-0,38) + 3,15`
`= 2,77`
`d) \sqrt{\sqrt{\sqrt{\sqrt{\sqrt{25^64}}}}}`
`= \sqrt{\sqrt{\sqrt{\sqrt{25^32}}}}`
`= \sqrt{\sqrt{\sqrt{25^16}}}`
`= \sqrt{\sqrt{25^8}}`
`= \sqrt{25^4}`
`= 25^2 `
`= 625`
(Chúc bạn học tốt)
