Answer:
For x² + kx + 16/9 to be a perfect square, k should be equal to 8/3
Explanation:
If x² + kx + 16/9 is a perfect square then it must satisfy the formula of (a + b)² i.e. equal to a² + 2ab + b².
So, first we will form a equal that looks similar to the formula:

Now by comparing we get,
