X = Minutes used.
Y = T0tal cost in Dollars.
(X,Y), (20,48), (35,54), (40,56).
m = (Y2-Y1)/(X2-X1)=(54-48)/(35-20) =
0.40 = Slope.
(20,48)
Y = mX + b = 48
0.4*20 + b = 48
b = 40
Eq: Y = 0.4X + 40
My problem says
The cost of a cell phone for one month is a linear function of the numbers of minutes used. The total cost for 20, 35, and 40 additional numbers Re shown.
Then it gives a table where it's 20/48$, 35/54$ and 40/56$
The first question is ,
Find the linear equation that represents the relationship between the number of additional minutes and total cost
1 answer