bonsoir
f ( -3) = - 3 et f ( 1 ) = - 1
( - 1 + 3) / ( 1 + 3 ) = 2 /4 = 1/2
ax = x /2
f ( - 3) = - 3
- 3 * 1/2 + b = - 3
- 3 /2 + b = - 3
b = - 6 /2+ 3 /2 = - 3 /2
f (x) = 0.5 x - 1.5
f ( 1 ) = 1 * 0.5 - 1.5 = 0.5 - 1.5 = - 1
g ( - 1 ) = 4 et g ( 4 ) = - 2
( - 2 - 4 ) / ( 4 + 1 ) = - 6 /5
ax = - 6 x / 5
g ( - 1 ) = 4
- 1 * - 6 /5 + b = 4
6/5 + b = 4
b = 4 - 1.2 = 2.8
g (x) = - 6 x/5 + 2.8
g ( 4) = 4 * - 6/5 + 2.8 = - 24/5 + 2.8 = - 4.8 + 2.8 = - 2
