Bonsoir,
A=1/11-(-5/4
)
A = 1/11 + 5/4
A = (1 x 4) / (11 x 4) + (5 x 11) / (4 x 11)
A = 4/44 + 55/44
A = 59/44
B=-4/21+7/3
B = - 4/21 + (7 x 7) / (3 x 7)
B = - 4/21 + 49/21
B = 45/21
B = (3 x 15) / (3 x 7)
B = 15/7
C=10/8+-5/40
C = (10 x 5) / (8 x 5) - 5/40
C = 50/40 - 5/40
C = 45/40
C = (5 x 9) / (5 x 8)
C = 9/8
D=-3/12+-7/8
D = (- 3 x 2) / (12 x 2) - (7 x 3) / (8 x 3)
D = - 6/24 - 21/24
D = - 27/24
D = (3 x - 9) / (3 x 8)
D = - 9/8.
