Select all that apply. Which representations show a direct variation?

y = - x

y = 2 x + 3

Input (x) 3 6 9 12 15
Output (y) 4 8 12 16 20

Step-by-step explanation:

Direct variation is:

Options:

1.

2.

3.

Try the input/output to determine the direct variation:

Verify the other pairs:

This is also a direct variation

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is