Question

1,2+3,10у=8/15у+0,78

Answer 1

3,1у-8/15у=0,78-1.2
31/10-8/15=93/30-16/30=77/30
77/30у=-21/50
у=-21/50: 77/30
у=- 21*30/50*77
у=-9/55