bonsoir
f ( 2 ) = - 2 et f ( - 2 ) = 3
( 3 + 2 ) : ( - 2 - 2 ) = 5 / - 4
ax = - 5 x /4
f (2) = - 2
2 * - 5/4 + b = - 2
- 10 /4 + b = - 2
b = - 8/4 + 10 /4 = 2/4 = 1 /2
f (x) = - 5 x /4 + 1 /2
f ( - 2 ) = - 2 * - 5/4 + 1 /2 = 10 /4 + 2/4 = 12 /4 = 3
bonne soirée