Question

Determine whether y varies directly with x. y-2x=0

Answer 1

hi,  
you can determine it by seeing if y/x = a constant value, in other words if y = (a constant value) x 
then you say that y varies directly with x, and you can see that : call the constant k 
then y/x is supposed to be k in all values 
6/3 = 2 
24/12 =2  
96/48 = 2 
384/192 = 2 
it worked the ratio between x and y is constant so y varies directly with x ( y = 2x) and that constant k =2 
p.s. you can also say that x varies directly with y but in that case it becomes x/y =constant and that constant say c is 1/2 (x = (1/2)y)) 
hope u understand.

Source- https://answers.yahoo.com/question/index?qid=20110813112602AApHZtQ

Answer 2

No because when y is next to a number you mutiply and y you do what ever its next to