Question

Direct Variation question.

Y varies directly with X.

If y=25 when x=15, find y when x=6

Answer 1

the formula is y = kx. plug in 25 = k * 15 and solve for k. k = 5/3 Now use k in a new equation to solve for y. y = (5/3)(6) y = 10

Answer 2

Direct Variation:
y = kx

First find k using given (x,y)

25 = 15k    ----->  k = 25/15 = 5/3

Now plug in x = 6 and k=5/3  into function to get y value:

y = (5/3)(6) = 30/3 = 10