Answer:
-2
Step-by-step explanation:
Dividing the given equation by x, we find y to be ...
y = -2/x
Then ...
dy/dx = 2/x^2
and ...
dy/dt = (2/x^2)dx/dt
dx/dt = (x^2/2)dy/dt
When dy/dt = -4 and x=-1, this is ...
dx/dt = (-1)^2/2(-4) = (1/2)(-4)
dx/dt = -2
