W = k (x/y)
'k' is some constant number.
Chat with our AI personalities
Y = K (z/x)
The phrase "varies directly as" means that there is a number k such that w = k(2x - 1). From the results given for w = 9 when x = 2, 9 = k(4 - 1), or k = 3. Then when w is 15, 15 = 3(2x - 1), or 15 = 6x - 3, or 6x = 15 + 3, or x = 18/6 = 3.
If y varies directly as x then k = 2.
1
If y varies directly as x and if x = 2 when y = 8 then k = 4.