1,5х+31/3=2,5

1,5х=-1 1/6

х=-1 1/6 :1 3/6

х=- 7/6 *6/9

х=-7/9

2,5х+ 6,3 = 7 1/3

2,5х=220/30-189/30

2,5х=31/30

х=31/30*10/25

х=31/175