Let's look at the second equation and try multiplying it by 4:
4 * (3x + ky) = 4 * 27
Which gives us:
12x + 4ky = 108
This looks almost exactly like the first equation except that instead of -20y, there is 4ky. We could try making them equal to each other and solving for k:
-20y = 4ky
-20 = 4k
k = -5
Then, the answer is k = -5.
