Which equation represents a direct variation

Direct variation is is when the x and y a direct relation

without constants added or subtracted

With being times by each other

so the only one that meets the definite is the first one

 y = 0.5x  means y is equal to half of x.  So you know that every y is directly related to half of x

Y=0.5

Step-by-step explanation: There can be no + or - .

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads

y = 5x + 17

step-by-step explanation:

a perpendicular line will be the opposite reciprocal slope of the given equation.   the slope given is -1/5 so the opposite reciprocal is 5

find b:

7 = 5 (-2) + b

7 = -10 + b

17 = b

write equation

y = 5x + 17