Which ordered pair would form a proportional relationship with the point graphed below? (–40, 20) (–10, –20) (15, –30) (5, –15)

Question

asked Sep 12, 2020 123k views

2 Answers

Matt Leach · Answer 1 · 2020-09-18T01:49:24+0000

Answer:

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.