x+3 = 2y+1 x+2 = 2y
x+5 = 2z+1 x+4 = 2z 2y+2 = 2z z = y+1
2) n = 96a + 69 n:32 = 3a + 69:32 69:32 = 2x32 + 5 r = 5
3) 10! = 1·2·3·4·5·6·7·8·9·10
9! = 1·2·3·4·5·6·7·8·9 10! + 9! = 1·2·3·4·5·6·7·8·9·10·11
10!-9! = 1·2·3·4·5·6·7·8·9·9 (10!+9!)/(10!-9!) = 10·11/9 = 110/9 = 12 rest 2
4) 3x + 2y = 15 6x + 4y = 30
y + 3z = 17 3y + 9z = 51
-------------------
6x + 7y + 9z = 81