Answer:
Second from top...
The average rate of change is $0.07, meaning that for each minute of talk time, the monthly bill increases by $0.07.
Step-by-step explanation:
Pick any two points and calculate the slope which will represent the rate of change:
(Minutes, Cost)
(0, 9.95)
(10, 10.65)
Rate of change:
slope m = (y₂ - y₁) / (x₂ - x₁)
= (10.65 - 9.95) / (10 - 0)
= 0.7 / 10
= 0.07
y is cost
m is rate of change
x is minute(s) use
b is fixed monthly cost regardless if any minutes is used
y = mx + b
y = .07x + 9.95
Inversely proportional: z = k/r
k = 32 * 1.5 = 48
Plug that into equation
8 = 48/r
Multiply both sides by r
8r = 48
Divide by 8
r = 6
Answer:
it's the first one and the third one
Step-by-step explanation:
cause 6 (X - 4) multiply by 6 by X and 4
and same for the third expression.
Unfortunately you have not included the directions. Are you supposed to solve for x? or for y?
Suppose the directions say, "Solve for x." Then, clear out the decimal fraction by mult. both sides of the given equation by 10. This will give you the solution, that is, a formula for x in terms of y.
