Bonjour

a. 17/- 24 + (- 5/36)

= (17 x 3) / (24 x 3) - (5  x 2) / (36 x 2)

= 51/72 - 10/72

= 41/72

b. 3/16 - - 1/12

= (3 x 3) / (16 x 3) + (1 x 4) / (12 x 4)

= 9/48 - 4/48

= 5/48

c. 8/- 17 - (- 1/15)

= (- 8 x 15) / (17 x 15) + (1 x 17) / (15 x 17)

= - 120/255 + 17/255

= - 103/255

d. 2/5 + - 2/15 - 7/12

= (2 x 12) / (5 x 12) - (2 x 4) / (15 x 4) - (7 x 5) / (12 x 5)

= 24/60 - 8/60 - 35/60

= - 19/60.

Bonjour,

a)

17/-24 * 36/36  =  -612/864 = -306/432

-5/36 * 24/24 =  -120/864 = -60/ 432

-  306/432 - 60/432

=  366/432 =  -122/144 = - 61/72

b)

3/16 *12/12 = 36/192

- 1/12 * 16/16 = -16/192

36/192 + 16192

= 52/192 = 26/96 = 13/48

c)

-8/17 * 15/15 =-120/ 255

1/15 *17/17 = 17/255

-120/255 + 17/255

= -103/255

d)

2/5 = 6/15

6/15 -2/15 = 4/15

4/15 -7/12

48/ 180 - 105/ 180

= - 57/180 = -19/60