Find Decreasing Intervals for y = -2x² - 8x - 10

To determine where the function $y = -2x^2 - 8x - 10$ is decreasing, we need to find the vertex of the parabola. The vertex for a quadratic function in the form $y = ax^2 + bx + c$ occurs at the x-value given by $x = -\frac{b}{2a}$.

Step 1: Identify the coefficients $a = -2$ and $b = -8$.

Step 2: Calculate the vertex x-coordinate:

$x = -\frac{-8}{2(-2)} = -\frac{8}{-4} = 2$.

Step 3: Since $a = -2$ is negative, the parabola opens downwards. Thus, the function decreases for x-values greater than $x = -2$.

Therefore, the interval where the function is decreasing is $x > -2$.

The correct choice is $x>-2$.