a, ( 5/24 + 0,75+ 7/2 ) : ( -2 1/8 )
= (5/24 + 3/4 + 7/2) : (-17/8)
= 107/24 x (-8/17)
= -107/51
b, 2/3+ 20% . 10/7
= 2/3 + 1/5 . 10/7
= 2/3 + 2/7
= 20/21
c) đề
= đề có sai kh ạ>

a, (5/24 + 0,75 + 7/2) : (-2 1/8)
= (5/24 + 3/4 + 7/2) : (-15/8)
= 107/24 : (-15/8)
= -107/45
b, 2/3 + 20% . 10/7
= 2/3 + 1/5 . 10/7
= 2/3 + 2/7
= 20/21
c, 6/7 + 8/13 . 6/13 + 9/7 - 4/13 . 6/7
= 6/7 + 8/13 . 6/7 + 9/13 - 4/13 . 6/7
= 6/7 . (8/13 + 9/13 - 4/13)
= 6/7 . 1
= 6/7