Решите уравнения:

1) 5 3/7 - (b-2 1/7) = 2 4/7

2) (270:y-12) * 70=1260

(5*7+3) / 7-7*b/7 + (2*7+1) / 7 = (2*7+4) / 7

38-7b+15=18

-7b=18-15-38

b=-1 * (18-15-38) / (7)

b=35/7=5

270*70/y-840=1260

18900/y=1260+840=2100

y=18900/2100=9

1) 5 3/7 - (b-2 1/7) = 2 4/7

38/7 - b + 15/7 = 18 / 7

b = 38/7 + 15/7 - 18/7

b = 38+15-18 / 7

b = 35/7

b = 5

2) (270:y-12) * 70=1260

(270:y-12) = 1260:70

270:y-12 = 18

270:y = 18+12

270:y = 30

y = 270:30

y = 9