Suatu fungsi linear f(x) = ax+b, jika f(1) = 3 dan f(2) = 4. maka bentuk Fungsi f(x) adalah

F(x)=ax + b
f(1) = a + b = 3
f(2) = 2a + b = 4
         ————– ( – )
          -a = -1
           a = 1

f(1) = 1 + b = 3
b = 3 – 1
b = 2

jadi fungsi f(x) adalah f(x) = x + 2

F(x) = ax + b
f(1) = a(1) + b
3 = a + b

f(2) = a(2) + b
4 = 2a + b

  a + b = 3
2a + b = 4
————- –
<=> -a = -1
<=> a = 1

a + b = 3
1 + b = 3
b = 3 – 1
b = 2

f(x) = 1x + 2
f(x) = x + 2