Find Increasing Intervals for y = -x² + 10x - 16: Quadratic Function Analysis

To solve this problem, we'll begin by finding the derivative of the function.

The given function is $y = -x^2 + 10x - 16$.
The derivative is:

$y' = \frac{d}{dx}(-x^2 + 10x - 16) = -2x + 10$.

Now, we want to find where this derivative is greater than zero:

$-2x + 10 > 0$.

Solving this inequality, we have:

$-2x > -10$
$2x < 10$
$x < 5$.

Therefore, the function is increasing for $x < 5$.

Hence, the correct answer is $x < 5$.