bonjour, pouvais vous m'aider pour mon dm de math ?

1.
a. (1/3)(x+2)=5/6 => x+2=5/2 => x=(5-4)/2=1/2
b. (½)(3x-1)=5/4 => 3x-1=5/2 => 3x=7/2 => x=7/6
c. (3/7)(4x+5)=6/7 => 4x+5=2 => x=-3/4
2.
a. (14/3)(6/5)(15/7)=(2*7*2*3*3*5)/(2*7*5*7)=2*3*3/7
=18/7
b. (1-5/2)/(6-4/3)=(1-5/2)/(5-1/3)=[6*(1-5/2)]/[6*(5-1/3)]
=(6-15)/(30-2)=-9/28
c. 8/9+11/3=(8+33)/9=41/9
d. 7/8-31/5=(35-248)/40=-213/40