For which value of k are the points (0 -5) (6 k) and (-4 -13) collinear?

Step-by-step explanation:

Use the 2 points for which you have both an x and y coordinate to write the equation of the line containing those 2 points.  When you get the equation, sub in the x value of 6 and solve for y.  

Begin by finding the slope of the line:

Then use one of the points in point slope form to write the equation in slope-intercept form.  I used (0, -5).  But either point you choose will give you the exact same line...promise.

y - (-5) = 2(x - 0) and

y + 5 = 2x and

y = 2x - 5

Now sub in the x value of 6 for x and solve for y:

y = 2(6) - 5 and

y = 12 - 5 so

y = 7

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

source

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