1)- в=0,5 2)7х=3,5 3)2у-=1 4)+х= 5)- а=а+2

(5/6)b=0.5=1/2
b=1/2:5/6=6/10=3/5

7x=3.5
x=3.5/7=0.5

2y-5/8=1
2y=1+5/8=13/8
y=(13/8):2=13/16

3/4+(2/3)x=1/2
(2/3)x=1/2-3/4=2/4-3/4=-1/4
x=(-1/4):2/3=-3/8

(5/6)a=(2/3)a+2
(5/6)a-(2/3)a=2
(5/6)a-(4/6)a=2
(1/6)a=2
a=2:(1/6)=12