35у+33у - 198=6942 (2а+4)*5-(3а-4)*7=147 (х-63580): 5=3107

35у+33у - 198=6942
35у+33у =7140
68у=7140
y=105

(2а+4)*5-(3а-4)*7=147
10a+20-21a+28=147
-11a=147-20-28
-11a=99
a=-9

(х-63580):5=3107
х-63580=15535
x=15535+63580
x=79115