Réponse :
f(1) = 3 f(7) = 15 f(-4) = -7 f(-3/2) = -2
f(0) = 1
f(-3) = -5
Explications étape par étape :
a) f(1) = 2*1 + 1 = 3
f(7) = 2*7 + 1 = 14 + 1 = 15
f(-4) = 2*(-4) + 1 = -8 + 1 = -7
f(-3 demi) = 2*(-3/2) + 1 = -3 + 1 = -2
b) f(0) = 2*0 + 1 = 0 + 1 = 1
f(x) = -5
On sait que f(x) = 2x + 1 donc 2x + 1 = -5
2x + 1 - 1 = -5 -1
2x = -6
2x/2 = -6/2
x = -3