Question

Tolong kasih tau caranya dong, Diketahui rumus fungsi f(x)=ax+b. Jika f(2)=-2 dan f(-3)=13 maka nilai f(4) adalah...

Answer 1

A=3
b= -8

f(4)=3.4 + -8
     =12 + -8
     = 4

Answer 2

F (x) = ax + b
f (2) = -2
F (2) = a(2) + b
-2  =  2a + b

f(-3) = 13
f (-3) = a(-3) + b
13 = -3a + b

2a + b = -2
-3a + b = 13
-------------------------- _
5a       = - 15
        a = -15 / 5
        a = -3

2a + b = -2
2 (-3) + b = -2
-6 +b = -2
b = -2 + 6
   = 4

f(4) = ax + b
     = -3(4) + 4
     = -8