8th grade
posted by gavyn on .
i have a homework assignment i do not know how to do. i was out sick so i have not learned this. hear is the question......y varies directly as x. find the constant of variation and write an equation for the direct variation.
question 1: y=15 when x=5

direct variation:
y= kx where k is the constant of variation.
15=k*3 find k. 
y=kx
y=15
x=5
Shouldn't it be 15=k*5? 
The anwser is y=3x
Becasue all you doing is divding 15 dy 5 to get k