Answer:
If y varies directly as x, we can express this relationship with the equation y = kx, where k is the constant of variation.
To find the value of k, we can use the given information that y = -40 when x = 5. Substituting these values into the equation, we have:
-40 = k * 5
To solve for k, we divide both sides of the equation by 5:
k = -40 / 5
k = -8
Now that we have the value of k, we can use it to find the value of x when y = -4. Substituting the known values into the equation, we have:
-4 = -8x
To solve for x, we divide both sides of the equation by -8:
x = -4 / -8
x = 0.5
Therefore, when y = -4, the value of x is 0.5.
