Which linear equation shows a proportional relationship?

A. [tex]y = \frac{1}{7}x - 2[/tex]
B. [tex]y = -\frac{1}{7}x[/tex]
C. [tex]y = -7x + 3[/tex]
D. [tex]y = 7[/tex]



Answer :

To determine which linear equation shows a proportional relationship, we need to look for an equation of the form [tex]\( y = kx \)[/tex], where [tex]\( k \)[/tex] is a constant and there is no other term added or subtracted.

Let's analyze each given option one by one:

1. [tex]\( y = \frac{1}{7}x - 2 \)[/tex]
- This equation includes an additional constant term (-2), which means it is not a purely proportional relationship. A proportional relationship doesn't have an extra constant term added or subtracted.

2. [tex]\( y = -\frac{1}{7}x \)[/tex]
- This equation is in the form [tex]\( y = kx \)[/tex], where [tex]\( k = -\frac{1}{7} \)[/tex]. There are no additional constant terms. This equation represents a proportional relationship.

3. [tex]\( y = -7x + 3 \)[/tex]
- Similar to the first option, this equation includes an additional constant term (+3), so it is not a purely proportional relationship.

4. [tex]\( y = 7 \)[/tex]
- In this equation, [tex]\( y \)[/tex] does not depend on [tex]\( x \)[/tex]. It represents a constant value and does not show a proportional relationship.

Given this analysis, the correct linear equation that shows a proportional relationship is:

[tex]\[ y = -\frac{1}{7}x \][/tex]

Therefore, the correct option is the second one.