Bonjour,

Ex. 1 :

1) a = (11-7)/(2-4) = -2

2) h(4)=7 ⇒ -2(4)+b=7 ⇒ b=7+8=15

3) h(x)=-2x+15

Exercice 1:

1) a = (7 - 11)/ (4 - 2) = -4/2 = -2

2)on a:        h(4) = - 2 × 4 + b = 7

Donc:     b = 7 + 8 = 15

3) h(x) = - 2 x + 15

Exercice 2:

On a :      a= (-3 - 8)/ (7 + 15)

                 = -11/22 = - 1/2

On a:   j(-3)= 3/2 + b = 7

     Donc:   b = 7 - 3/2 = 11/2

Alors:     j(x) = - 1/2 x  + 11/2

2)  j(5) = - 5/2  + 11/2 = 6/2 = 3

Exercice 3:

1) g(x) = ax + b

   g(0) = b = - 9

2) on a: g(-2) = - 2a - 9 = 5

    Donc: a est une solution de

      -2a - 9=5

3) on a: a = (5+9)/-2 = - 7

     Donc: g(x) = - 7x - 9

Exercice 4:

1) h(0) = b = - 7

On a:    h(3) = 3a - 7 = -52

Donc:   a = (-52 + 7)/3  = -55/3