Réponse:
S = -15/28 : -25/42
S = -15/28 x (-42/25)
S = 15/28 x 42/25
S = 15/25 x 42/28
S = (3x5) /(5x5) x (3x14) /(2x14)
S = 3/5 x 3/2
S = 9/10
T = 63/44 : (-72/55)
T = 63/44 x -55/72
T = (-55/44) x 63/72
T = (-5x11) / (4x11) x (9x7) / (9x8)
T = -5/4 x 7/8
T = -35/32
U = 12/(45/16)
U = 12 x 16/45
U = (3x4) x 4 x 4 / (3x15)
U = 64/15
V = -48/(32/21)
V = -48 x 21/32
V = -48/32 x 21
V = (-3x16) / (2x16) x 21
V = (-3/2) x 21
V = -63/2
W = -5/12 + 7/12 : 5/18
W = -5/12 + 7/12 x 18/5
W = -5/12 + 7/5 x 18/12
W = -5/12 + 7/5 x (3x6) / (2x6)
W = -5/12 + 7/5 x 3/2
W = -5/12 + 21/10
W = (-5x5) / (12x5) + (21x6) /(10x6)
W = -25/60 + 126/60
W = 101/60
X = (-1/24-(-2/24)) / (-3/8-1)
X = (-1/24 + 2/24) / (-3/8 - 8/8)
X = 1/24 / (-11/8)
X = 1/24 x (-8/11)
X = -8/24 x 1/11
X = -1/3 x 1/11
X = -1/33
