bjr . pour le 52 aider moi svp

A=2x+4-(8x-9)
A=2x+4-8x+9
A=-6x+13

B=3a-7+(2a+5)+(3a-10)
B=3a-7+2a+5+3a-10
B=8a-12

C=3t+0,1-(4,5-6t)+[12-(3,2+t)]
C=3t+0,1-4,5+6t+(12-3,5-t)
C=3t+0,1-4,5+6t+(12-3,5-t)
C=8t+4,1