The value of y when x = 4 is:
y = 4k - 2
The value y when x = 6 is:
y = 6k - 2
The first is 5 less than the second:
(4k - 2) = (6k - 2) - 5
4k = 6k - 5
2k = 5
k = 2.5
Now we know the constant; the equation is:
y = 2.5x - 2
When x = 24:
y = 2.5(24) - 2
y = 60 - 2 = 58, choice (B).