Question

Which ordered pair would form a proportional relationship with the point graphed below?

(–40, 20)

(–10, –20)

(15, –30)

(5, –15)

Answer 1

(15, -30)

Step-by-step explanation:

because it will go through the orgin in a straight line.

Answer 2

Option C.

Explanation:

A proportional relationship is defined as

`y\propto x`

`y=kx`

where, k is the constant of proportionality.

From the given graph it is clear that there is proportional relationship with the point (-20,40).

Substitute x=-20 and y=40 in the above equation to find the value of k.

`40=k(-20)`

Divide by -20.

`-2=k`

The value of k is -2. So, the proportional relationship is defined as

`y=-2x`

At x=-40,

`y=-2(40)=-80`

It means point (-40,20) would not form a proportional relationship with the (-20,40).

Similarly,

At x=-10,

`y=-2(-10)=20`

At x=15,

`y=-2(15)=-30`

At x=5,

`y=-2(5)=-10`

It means points (-10,-20) and (5,-15) would not form a proportional relationship with the (-20,40).

Only point (15,-30) would form a proportional relationship with the (-20,40).

Therefore, the correct option is C.