D is partly constant and partly varies with y.when y=6,x=9.Find the relationship between xandy.Find x when y=4.

x = 5 + 2/3y

Where does D enter the picture?

Check the wording of your original question.

To find the relationship between x and y, as well as find the value of x when y equals 4, we need more information. Specifically, we need to know how D varies with y and what "partly constant" means in this context.

Assuming that "partly constant" means that D has a fixed value for some range of y values and varies for others, we can create an equation to represent the relationship between x and y.

Let's say that when y is in the range of y1 to y2, D has a constant value of c. In this case, we can write:

D = c for y1 ≤ y ≤ y2

And when y is outside this range, D varies with y. Let's say D can be represented as a linear function of y when it varies:

D = mx + b when y < y1 or y > y2

Where m and b are constants representing the slope and y-intercept of the linear function, respectively.

Now, let's use the given information that when y = 6, x = 9. Since we don't have information about the range of y values for which D is constant, we can't determine the values of c, y1, and y2, or the slope and y-intercept of the linear function. Therefore, without more information, we cannot establish the exact relationship between x and y, nor can we determine x when y = 4.

If you have additional information about the relationship between D, x, and y, please provide it so we can give you a more accurate answer.