f(x) = (2k+1) x + 7 jika, f(-1) = -4 f(k) = ?

f(x) = (2k + 1) x + 7
f(-1) = (2k + 1) (-1) + 7
-4 = -2k - 1 + 7
2k = 4 + 6
k = 10 : 2
k = 5

untuk f(x) = (2(5) + 1) x + 7 = 11x + 7

maka f(x) = 11x + 7
untuk f(k) = 11k + 7