Diketahui f(x) fungsi linear. jika f(3x+4)=6x+1,nilai f(3) adalah​

f(3x+4) = 6x+1

f(3) = ?

3x + 4 = 3

3x = -1

x = -1/3

f(3) = f(3.(-1/3)+4) = 6.(-1/3)+1

f(3) = -2+1

f(3) = -1

cara 2 : ubah f(3x+4) jadi f(x)

3x+4 = a

3x = a-4

x = (a-4)/3

f(x) = f((a-4)/3)

f(a-4/3) = 6(a-4/3) + 1

            = 2(a-4) + 1

           = 2a – 8 + 1

          = 2a – 7

f(x) = 2x-7

f(3) = 2.3 – 7 = -1