(5а-0.5)/4-(3+4а)/5=(4-7а)/3-(11а-1.5)/6

5а:4-0,125-(0,6-4а:5)=1 1/3-2 1/3а-(1 5/6а-0,25)

1 1/4а-0,125-0,6+4/5а=1 1/3-2 1/3а-1 5/6а+0,25

1 1/4а+4/5а+2 1/3а+1 5/6а=1 1/3+0,25+0,125+0,6

6 13/60а=2 37/120

а=2 37/120:6 13/60

а=277/746 

(5a-0.5)/4-(3+4a)/5=(4-7a)/3-(11a-1.5)/6

1.25a-0.125-(0.6+0.8a)-(4-7a)/3+(11a-1.5)/6=0

0.45a-0.725-(4-7a)/3+(11a-1.5)/6=0

0.45a-247/120+7/3a+(11a-1.5)/6=0

277/60a-277/120=0

a=(277/120)/(277/60)

a=0.5