Question

Suppose that y varies directly with x and inversely with z, and y = 18 when x = 15 and z = 5. Write the equation that models the relationship. Then find y when x = 21 and z = 7.

Answer 1

y directly varies with x, so u can write y=mx
y inversely varies with z, so u can write y=n/z
overall u can write
\(y=\frac{kx}{z}\)
now put,y=18,x=15,z=5 to find k.
can u find k ?

Answer 2

So Far i have 18=k5/k

Answer 3

were do i go from here

Answer 4

how did u get that?
18=k(15/5)
18=k(3)
k=18/3=6
ok till here?