Bonsoir
A = 15/7 - 9/7
A = (15 - 9)/7
A = 6/7
B = -3/8 - 15/8
B = (-3 - 15)/8
B = (-18/8)
B = (-2 x 9)/(2 x 4)
B = -9/4
C = -4/7 + 2/3
C = (-4 x 3)/(7 x 3) + (2 x 7)/(3 x 7)
C = -12/21 + 14/21
C = (-12 + 14)/21
C = 2/21
D = 4/9 - 7/54
D = (4 x 6)/(9 x 6) - 7/54
D = 24/54 - 7/54
D = (24 - 7)/54
D = 14/54
D = (2 x 7)/(2 x 27)
D = 7/27
E = 5/6 - 9/8
E = (5 x 4)/(6 x 4) - (9 x 3)/(8 x 3)
E = 20/24 - 27/24
E = (20 - 27)/24
E = (-7/24)
F = 5/12 + 3/4
F = 5/12 + (3 x 3)/(4 x 3)
F = 5/12 + 9/12
F = (5 + 9)/12
F = 14/12
F = (2 x 7)/(2 x 6)
F = 7/6
G = 2 - 3/7
G = (2 x 7)/7 - 3/7
G = 14/7 - 3/7
G = 11/7
H = 4/3 + 1/6 - 7/12
H = (4 x 4)/(3 x 4) + (1 x 2)/(6 x 2) - 7/12
H = 16/12 + 2/12 - 7/12
H = 18/12 - 7/12
H = 11/12
