bonsoir
A = - 6 t + 15 t² - 4 + t² - 5 t + 12 t - 28 t² - 15 + 35 t - 10 + 3 t² - 21 + 7t
A = - 9 t² + 39 t - 50
E = 6 x² - 6 x - ( 6 x² - 4 x - 12 x + 8 )
E = 6 x² - 6 x - 6 x² + 16 x - 8
E = 10 x - 8
8 x² - 12 x = 4 x ( 2 x - 3 )
15 ab - 10 b² = 5 b ( 3 a - 2 b )
( x + 3 ) ( 5 - x )
( x + 1 ) ( 5 x - 2 - 2 x + 3) = ( x + 1 ) ( 3 x + 1 )