Which equation represents a proportional relationship between the x and y values?A) y = 2 B) y = 14x + 1 C) y = x − 4 D) y = −2x
Accepted Solution
A:
Answer:D) [tex]y=-2x[/tex]Step-by-step explanation:A linear relationship is of the form [tex]y=mx+b[/tex], where, [tex]m[/tex] is the slope and [tex]b[/tex] is the y-intercept (constant).
For a proportional relationship, the value of [tex]b=0[/tex] and thus it is of the form [tex]y=mx[/tex]
Let us check each option and express it in the form above.
Option A:
[tex]y=2[/tex]This can be written as [tex]y=0x+2[/tex]. So, [tex]b\ne 0[/tex].Since, b \ne 0, therefore, it is not a proportional relationship.
Option B:
[tex]y=14x+1[/tex]
Here, [tex]b=1[/tex]. So, [tex]b\ne 0[/tex].Since, b \ne 0, therefore, it is not a proportional relationship. Option C:
[tex]y=x-4[/tex]
Here, [tex]b=-4[/tex]. So, [tex]b\ne 0[/tex].Since, b \ne 0, therefore, it is not a proportional relationship. Option D:
[tex]y=-2x[/tex]This can be rewritten as [tex]y=-2x+0[/tex]There is no y-intercept on this. So, [tex]b=0[/tex]
Since,[tex] b = 0[/tex], therefore, it is a proportional relationship.
Therefore, the correct option is D.