Question

Answer 1

Bài 7

a) A = 1/3 . 4/5 + 1/3 . 6/5

= 1/3 . (4/5 + 6/5)

= 1/3 . 2

= 2/3

b) B = 1/8 . 3/7 + 1/8 . 4/7

= 1/8 . (3/7 + 4/7)

= 1/8 . 1

= 1/8

c) C = -5/6 . 4/19 - 7/12 . 4/19

= 4/19 . (-5/6 - 7/12)

= 4/19 . (-17/12)

= -7/57

Answer 2

Bài 8

a) (5/2 - 4/3) . 9/14

= 7/6 . 9/14

= 3/4

b) 5/2 . (2/3 - 1/4)

= 5/2 . 5/12

= 25/24

c) (5/2 + 11/8) . (8/3 - 20/15)

= 31/8 . 4/3

= 31/6