diketahui fungsi f(x)=2x+3.jika f(k)=9,nilai k adalah...

f(x) = 2x + 3 maka f(k) = 2k + 3 
2k + 3 = 9 
2k = 6 
k = 3

f(x) = 2x + 3
f(k) = 2k + 3 = 9
=> 2k + 3 = 9
=> 2k = 9 - 3
=> 2k = 6
=> k = 6/2
=> k = 3

Jadi nilai k adalah 3