Réponse :

a)

Explications étape par étape

Exercice 1 =

a)1) A = 5x - 3

Si x = - 1

A = 5 x (-1) - 3

A = - 5 - 3

A = -8

B = 2x²-5x + 4

Si x = -1

B = 2 x (-1)² - 5 x (-1) + 4

B = 2 x 1 - (-5) + 4

B = 2 + 5 + 4

B = 11

2) Si x = 3

A = 5x3 - 3

A = 15 - 3

A = 12

B = 2x 3² - 5x3 + 4

B = 2x9 - 15 +4

B = 18 - 15 + 4

B = 7