Y=5x²

Question

y is not proportional to x however y is proportional to x² =y/x² 5 is a constant
QNo2 If x is directly proportional to y²,when x=9 and y= 3 if y=5 , find x
Solution..
X=Y²
Formula
X¹/ Y¹ =X² /Y²
X¹=9
X²=?
Y¹=3
Y²=5
X¹ Y²=X² Y¹
(9) (5)= x² (3)
45 /3 = x²
X² = 15