CPM Homework Help : CC2 Problem 6-108

Which of the equations below represent proportional relationships? If the relationship is proportional, identify the constant of proportionality. If the relationship is not proportional, explain why.

$y = \frac { 3 } { 4 } x + 2$
Hint (a):
A proportional relationship should involve only multiplication. Does this equation fit that description?
Answer (a):
Not proportional, since there is addition.

$y = ( 4 \frac { 2 } { 3 } ) x$
Hint (b):
There is only multiplication involved in this equation.
Answer (b):
Proportional; constant of proportionality is $4\frac{2}{3}$

$y=3(x-1)$
Hint (c):
This equation is equivalent to $y=3x-3$ .