Bonjour,
A= -2(3/4 + 2/5) + 3/2
A= -2(23/20) + 3/2
A= -23/10 + 3/2
A= -4/5
A= -2*3/4 -(-2*2/5) + 3/2
A= -3/2 -(-4/5) + 3/2
A= -3/2 + 4/5 + 3/2
A= -4/5
B= 4( 3/4 - 1/2) - (1/2 + 5/-6)
B=4 (1/4) - (-1/3)
B= 1 + 1/3
B=4/3
B= 4(3/4 - 1/2) - ( 1/2 + 5/-6)
B= 4*3/4 + 4*-1/2 - (1/2 + 5/-6)
B= 3 + (-2) - (1/2 + 5/-6)
B= 1 - ( -1/3)
B= 1 + 1/3
B= 4/3