Bonsoir! Est ce que quelqu'un peut m'aider avec cette exercice?

Bonjour

S = - 15/28 : - 25/42

S = - 15/28 x - 42/25

S = 630/700

S = (70 x 9) / (70 x 10)

S = 9/10

T = 63/44 : - 72/55

T = 63/44 x - 55/72

T = - 3 465/3 168

T = (99 x - 35) / (99 x 32)

T = - 35/32

U = 12 : 45/16

U = 12 x 16/45

U = 192/45

U = (3 x 64) / (3 x 15)

U = 64/15

V = - 48 : 32/21

V = - 48 x 21/32

V = - 1 008/32

V = (16 x - 63) / (16 x 2)

V = - 63/2

W = - 5/12 + 7/12 : 5/18

W = - 5/12 + 7/12 x 18/5

W = - 5/12 + 126/60

W = (- 5 x 5) / (12 x 5) + 126/60

W = - 25/60 + 126/60

W = 101/60

X = (1/24 - - 2/24) : (- 3/8 - 1)

X = (1/24 + 2/24) : [- 3/8 - (1 x 8) / (1 x 8)]

X = 3/24 : (- 3/8 - 8/8)

X = (3 x 1) / (3 x 8) : (- 11/8)

X = 1/8 x - 8/11

X = - 8/88

X = (8 x - 1) / (8 x 11)

X = - 1/11.