19 7/17-(3 9/17+х)=5;у+7 29/31=6 21/31+8 19/31

1) 19 7/17 - (3 9/17 + х) = 5;

(19 * 17 + 7)/17 - (3 * 17 +  9)/17 - х = 5;

330/17 - 60/17 - х = 5;

х = (330 - 60)/17 - 5 = 270/17 - 5 * 17/17 = (270 - 85)/17 = 185/17;

Ответ: х = 185/17.

2) у + 7 29/31 = 6 21/31 + 8 19/31;

у + (7 * 31 + 29)/31 = (6 * 31 + 21)/31 + (8 * 31 + 19)/31;

у + (217 + 29)/31 = (186 + 21)/31 + (248 + 19)/31;

у + 246/31 = 207/31 + 267/31;

у = (207 + 267 - 246)/31 = 228/31;

Ответ: у = 228/31.