Controle demain comment factoriser svp

Pour faire simple : a x(b+c) = a x b + a x c
Exemple : 12 x (17 + 9) = 12 x 17 + 12 x 9 = 204 + 108 = 312

h = 3(2X+2) - X(X+1)
h = 3x2(X+1) - X(X+1)
h = 6(X+1) - X(X+1)
h = (X+1) (6-X)