dik rumus suatu fungsi f(x):ax+b,f(3):5f(-1):3.nilai dr f(4)adalah

Bab Fungsi
Matematika SMP Kelas VIII

f(x) = ax + b
f(3) = 3a + b = 5
f(-1) = -1a + b = 3
----------------------- -

4a = 2
a = 1/2

3a + b = 5
3 . 1/2 + b = 5
b = 5 - 3/2
b = (10 - 3)/2
b = 7/2

f(4) = 4 . 1/2 + 7/2
f(4) = 2 + 3 1/2
f(4) = 5 1/2

f(x)=ax+b
f(3)=a(3)+b=5
f(-1)=a(-1)+b=3

a(3)+b=5
a(-1)+b=3
--------------------- -
4a=8
a=8/4
   =2
3a+b=5
3.2+b=5
6+b=5
b=-1
f(4)=ax+b      
     =2.4 + (-1)
     = 8-1
     = 7