fungsi g ditentukan dgn rumus g(x) =ax+b. bila g(2)=1 dan g(4)=7, maka nilai a+2b

g(x) = ax + b
g(2) = 1
1 = 2a + b ...(1)
g(4) = 7
7 = 4a + b ...(2)
Eliminasi variabel b dgn (2) - (1):
6 = 2a
a = 3
Subtitusi a = 3 ke pers (1) utk mncari nilai b:
1 = 2a + b ...(1)
1 = 2(3) + b
1 = 6 + b
b = -5

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