Jon and Ed are discussing their cell phone plan for text messaging. Jon pays $20 a month for his phone and $0.15 per text message he sends. Ed’s cell phone costs $30 a month and $0.10 for each text message. Using the information above determine how many text messages they can send for their bill to be the same

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

b

step-by-step explanation: