Question

Which equation represents a proportional relationship?

Answer 1

Answer:

$y=15x$

$y=-x$

Step-by-step explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form $y/x=k$ or $y=kx$

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin

case A) $y=15x$

Is a linear equation that passes through the origin

therefore

The case A) represent a proportional relationship

case B) $y=-x$

Is a linear equation that passes through the origin

therefore

The case B) represent a proportional relationship

case C) $y=-5(x+1)$

Is a linear equation but not passes through the origin

therefore

The case C) does not represent a proportional relationship

case D) $y=5x+1$

Is a linear equation but not passes through the origin

therefore

The case D) does not represent a proportional relationship

Answer 2

Non-proportional :
Y=mx+b
C AND D
Proportional :
Y=mx/ y=kx
A AND B
you said which equation not equations so I think you messed up somewhere when providing the question because with the provided answer choices, there are 2 proportional relationships!