1)41 9/21+x=45 11/21
2)(9 21/63-x)-3 15/63=2 11/63

1)41 9/21+x=45 11/21

870/21 + x = 956/21

290/7 + x = 956/21

x = 956/21 - 290/7

x = 86/21

2) (9 21/63-x)-3 15/63=2 11/63

(588/63 - x) - 204/63 = 137/63

(28/3 - x) - 204/63 = 137/63

128/21 - x = 137/63 - 128/21

-x = 137/63 - 128/21

-x = - 247/63

x = 243/63