Đáp án+Giải thích các bước:
`7) (8/9)^7 : (16/3)^7`
`<=>(8/9 : 16/3)^7`
`<=>(8/9 . 3/16)^7`
`<=>(24/144)^7`
`<=>(1/6)^7`
`8)( 18/49)^5 : (9/7)^5`
`<=>(18/49 : 9/7)^5`
`<=>(18/49 . 7/9)^5`
`<=>(126/441)^5`
`<=>(2/7)^5`
`11) (2/3)^5 . ({-1}/2)^5`
`<=.(2/3 . - 1/2)^5`
`,=>({-2}/6)^5`
`<=>({-1}/3)^5`
`12) ({-15}/19)^6 . (38/9)^6`
`=({-15}/19 . 38/9)^6`
`=({-570}/171)^6`
`=({-10}/3)^6`
Sử dụng công thức: `(A/B)^n . (C/D)^n = (A/B . C/D)^n`
