Bài ` 3 : `

` 1) (8/9)^8 . (3/4)^8 = (8/9 . 3/4 )^8 = (2/3)^8 = 256/6561 `

` 2) (3/7)^12 : (21/5)^12 = (3/7:21/5)^12 = (5/49)^12 = (5^12)/(49^12) `

` 3) (-4/13)^5 . (26/5)^5 = (-4/13 . 26/5)^5 = (-8/5)^5 = ((-8)^5)/((5^5)^5) = (-32768)/(3125) `

` 4) (12/7)^4 . (35/16)^4 = ( 12/7 . 35/16 )^4 = ( ( 3 . 5 )^4 )/4 = (15^4)/(4^4) = 50625/256 `

` 5) (6/7)^13 . (49/18)^13 = ( 6/7 . 49/18 )^13 = (7/3)^13 = (7^13)/(3^13) `

` 6) (-1/4)^12 : (13/12)^12 = ( -1/4 : 13/12 )^12 = (-3/13)^12 = ((-3)^12)/(13^12) = (3^12)/(13^12 `

` text{#Antanezha} `