Which of the following x-y coordinates is a solution to the inequality y > 9x? (7, 67) (9, 81) (5, 42) (4, 37)

Question

I'm confused

Answer 1

So the inequality given was y>9x, we want to find the point where y is bigger than 9 times the x value

so we can just break down each points by multiplying the x coordinate by 9, and compare to the y value

for (7,67)

7*9=63, and 67 > 63 so (7,67) works

9*9=81, 81=81, so (9,81) doesn't work because we want y strictly greater

5*9=45, 45>42, so that doesn't work

4*9=36, 37 >36, so (4,37) works

so in the end, we have (7,67) and (4,37)

Answer 2

Make the following table:

x 9x y

7 63 67

9 81 81

5 45 42

4 36 37

From the table you can see that only for the coordinates (7,67) and (4,37) is y > 9x