6. if two quantities vary directly, which must be true of a graph showing the relationship between them?
a. the graph is a curve.
b. the graph increases from left to right.
c. the points on the graph are connected.
d. the points of the graph form a straight line, and the line must pass through the origin.

The points of the graph form a straight line, and the line must pass

through the origin ⇒ answer d

Step-by-step explanation:

* Lets explain the meaning of vary directly

- Direct variation is a relationship between two variables

- Two variable quantities have a constant ratio

- One of them equal the other multiplied by a constant

- If y varies directly with x, the y = kx, where k is the constant

 of variation

- The equation y = kx is represented graphically by a line

- If the value of x = 0 then the value of y must be equal zero, then the

 line which represented the direct variation must be passes through

  the origin

* Lets look to the answer to find the correct statement

a. The graph is a curve ⇒ Not true ⇒The graph must be line

b. The graph increases from left to right ⇒ Not true ⇒ maybe if the

    graph is a line there is no mention about the type of the graph

c. The points on the graph are connected ⇒ Not true ⇒ there is no

    mention about the type of the graph

d. The points of the graph form a straight line, and the line must pass

    through the origin ⇒ True ⇒ as we said above

* The answer is statement d

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq

the answer is b