Answer:
Step-by-step explanation:
[tex]z \alpha y \\z\alpha \frac{1}{\sqrt{x} } \\z \alpha \frac{y}{\sqrt{x} } \\z = \frac{ky}{\sqrt{x} } -------(1)\\\\5 = \frac{3k}{\sqrt{9} } \\ 5 = \frac{3k}{3} \\3k = 15\\k = 15/3\\k = 5\\Substitute 5 for k in eq 1\\z = \frac{5y}{\sqrt{x} }\\ z=?\\ y=18 \\ x = 25.\\z = \frac{5y}{\sqrt{x} }\\z = \frac{5(18)}{\sqrt{25} }\\z= \frac{90}{5} \\z = 18[/tex]
I hope i am correct