Answer:
If x-3 is directly proportional to the square of y, then we can say that:
(x-3) = ky^2
Where k is a constant of proportionality.
If x=5 when y=2, we can substitute these values into the equation to find the value of k:
(5-3) = k(2)^2
2 = 4k
k = 0.5
Now that we have the value of k, we can use it to find the value of x when y=6:
(x-3) = (0.5)(6)^2
x-3 = 18
x = 21
So, if x is directly proportional to the square of y and x=5 when y=2, then x=21 when y=6.