Bonsoir,
Il faut revoir ta leçon sur la double distributivité :
(a + b)(c + d) = ac + ad + bc + bd
B = (x + 9)(3 – 2x)
B = 3x – 2x² + 27 – 18x
B = –2x² – 15x + 27
C = (3y + 5)(10 + y)
C = 30y + 3y² + 50 + 5y
C = 3y² + 35y + 50
D = (z – 2)(3 – z)
D = 3y – z² – 6 + 2z
D = –z² + 5y – 6
E = 5(3g + 1)(g – 2)
E = (15g + 5)(g – 2)
E = 15g² – 30g + 5g – 10
E = 15g² – 25g – 10
