A- 13/4-(7/6-3/4)= ? B- (3/2-7/5)*(-5/6)-3= ? Merci de m'aider

A = 13/4 - ( 7/6 - 3/4) 
A = 13/4 - ( 14/12 - 9/12)
A = 13/4 - 5/12
A = 39/12 - 5/12 = 34/12 = 17/6

B = (3/2 - 7/5) x ( - 5/6) - 3
B = ( 15/10 - 14/10) x ( - 5/6) - 3
B = 1/10 x ( - 5/6) - 3
b = - 5/60 - 3
B = - 5/60 - 180/60 = - 185/60 = - 37/12