Rosa and maria are planning to make cupcakes to sell for a school fundraiser. rosa will sell hers for 15$ per dozen. maria plans to sell her cupcakes for $1.15 for each cupcake. what is the rate of change for rosa’s cupcakes?

So first you have to find the unit rate for Rosa's cupcakes.

The equation you will use is 15/12 = ?

The ? will be your unit rate.

So 15/12 equals 1.25

Maria sells hers for 1.15 each.

Rosa sells hers for 1.25 each.

1.25 -1.15 = 0.10

10 cents is your rate of change.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional