4. A cell phone company charges $50 for the
phone plus a monthly service charge of $30.
The equation y = 30x + 50 gives the cost y
after x months. Which is true of the relationship
between x and y?
A. It is linear and proportional.
B. It is linear and nonproportional.
C. It is not linear.
n. It is not linear and proportional,

do i do it on a graph?

step-by-step explanation:

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

step-by-step explanation: the answer for wha if rt is 10 centimeters long, and wha is st? it’s 6