Which of the following conditions in a quadrilateral proves it is a parallelogram?

a.) opposite sides are parallel
b.) opposite sides are equal in length
c.) opposite angles are equal (angles "a" are the same, and angles "b" are the same)
d.) angles "a" and "b" add up to 180°, so they are supplementary angles.

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: