je vous en supplie aidez moi !

a) 3x-1/2=-3/4-5x
3x+5x=-3/4+1/2
8x=-3/4+2/4
8x=-1/4
x=-1/(4*8)=-1/32

b) (1/4)x+5/2=-x+1
(1/4)x+x=1-5/2
(1/4)x+(4/4)x=(2/2)-(5/2)
(5/4)x=-3/2
x=(-3/2)*(4/5)=-(3*4)/(2*5)=-12/10=-6/5

c) -3/5+y=3/10-(1/2)y
y+(1/2)y=3/10+3/5
(2/2)y+(1/2)y=3/10+6/10
(3/2)y=9/10
y=(9/10)*(2/3)=(9*2)/(10*3)=(3*3*2)(2*5*3)=3/5

d) (5/2)a+1/4=(1/4)a+2/5
(5/2)a-(1/4)a=2/5-1/4
(10/4)a-(1/4)a=8/20-5/20
(9/4)a=3/20
a=(3/20)*(4/9)=(3*4)/(4*5*3*3)=1/15