5 Factorise puis réduis chaque expression.
A = (2x + 1)(x - 3) + (2x + 1)
A = (2x + 1)(x - 3) + (2x + 1) X......
A = (2x + 1) x....
A = ...
B = (3x + 2) - (2x - 7)(3x + 2)
C = -x - (3x - 2)x