Question

F(x) = ax +b
F(3)= 7
F(5)=15
Ditanya = F(-2)
=
guys tolong bantu ngerjakan ini ya, dg bnar, akan ku kasih nilai 30,
terima kasih,

Answer 1

F(x) = ax+b

f(3) = 3a+b = 7
f(5) = 5a+b = 15
_________________-
. -2a = -8
. a = 4

3a+b = 7
3(4)+b = 7
b = 7-12
b = -5

f(x) = 4x-5

f(-2) = 4(-2)-5
f(-2) = -8-5
f(-2) = -13

Answer 2

f(x) = ax + b
f(3) = 3a + b = 7
f(5) = 5a + b = 15
       ---------------------- -
         - 2a    = - 8
                a = 
                a = 4
5a + b = 15
5.(4) + b = 15
  20 + b  = 15
          b = 15 - 20
          b = - 5
jadi ,   f(x) = 4x - 5
        f(- 2) = 4.(- 2) - 5
                = - 8 - 5
                = - 13