let S(a)=2a be the function that calculates how many dollars you will spend if you buy x cans. (ex if a=3, so if you buy 3 cans, you will spend S(3)=2*3=6 dollars )
let P(a)=1.5a be the function that calculates how many dollars we you will spend on popcorns
you buy x soda and y popcorns, and you want x>y
we draw the line y=x, dashed, as we have a "strictly smaller than" inequality. The line y=x is the line containing (1, 1), (5, 5)... so (x, x). Any point below this line has x coordinate larger than the y coordinate, for example (5, 4.999), (5, 5) would be just on the line, and (5, 5.0001) just above the line.
So we color the region below the line y=x, with y=x dashed.
Next,
S(x)+P(y) = the total cost of buying x soda and y popcorn = 15
2x+1.5y=15,
1.5y=15-2x
[tex]y= \frac{15-2x}{1.5}=10- \frac{4}{3}x= - \frac{4}{3}x+10[/tex]
this is the line with slope -4/3, and y intercept = 10.
for the points (x, y) on this line, the cost is exactly 15 dollars, assuming x and y are real numbers (not whole numbers, as they should)
but the problem does not say that you have to spend 15 dollars, that is you can spend les, so the region below it is also colored.
the intersection of the 2 colored regions is the last picture
Answer: last picture