bonsoir
( 5 n - 10) /2 + 2 ( n + 2 )
= 2.5 n - 5 + 2 n + 4
= 4.5 n - 1
n + 3 + 2 n - 1 = 3 n + 2
( 9 n + 6 ) : 3 = 3 n + 2
( 4 n + 8) / 2 + n - 6
= 2 n + 4 + n - 6
= 3 n - 2
5 ( n + 4) - 2 ( n + 9)
= 5 n + 20 - 2 n - 18
= 3 n + 2
2 ( n - 2 ) - 4 ( n - 4 )
= 2 n - 4 - 4 n + 16
= - 2 n + 12
[6 ( n + 1) ] / 2 - 1
= ( 6 n + 6 ) / 2) - 1
= 3 n + 3 - 1
= 3 n + 2