#KhanhHuyen2006 - Xin câu trả lời hay nhất
Bài 1
`a) 47,57 . 12,38 + 12,38 . 52,43`
`= 12,38 . (47,57 + 52,43)`
`= 12,38 . 100`
`= 1238`
`b) 5/15 + 14/25 - 12/9 + 2/7 + 11/25`
`= 67/75 - 12/9 + 2/7 + 11/25`
`= -11/25 + 2/7 + 11/25`
`= -27/175 + 11/25`
`= 2/7`
Bài 2
`a) x - 1/4 = 23/14`
`-> x = 23/14 + 1/4`
`-> x = 53/28`
`b) |2,5 - x| = 1,3`
`->` \(\left[ \begin{array}{l}2,5 - x = 1,3\\2,5 - x = -1,3\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=1,2\\x=3,8\end{array} \right.\)
`c)`
Ta có : `2^{225} = (2^{15})^{15} = 32768^{15}`
Ta có : `3^{150} = (3^{10})^{15} = 59049^{15}`
`-> 32768 < 59049`
`-> 2^{225} < 3^{150}`
