Respuesta :

Answer:

A number or number sentence that doesn't change

Step-by-step explanation:

Answer:

the constant of proportionality k, is the constant value of the ratio of two proportional quantities y and x

Step-by-step explanation:

k = y/x or y= kx

example : the cost of 20 books is rs. 180 how much will 15 books cost ?

a. rs. 125

b. rs. 130

c. rs. 135

d. rs. 140

answer is c. rs. 135