Sensational Cell Phones offers a plan of $30 for the first 300 minutes, and an additional $0.30 for every minute over 300. Let t represent the total talk time in minutes. Write a piecewise-defined function that represents the cost of S(t) in terms of the number of minutes t that is used.

Since g(f(x))=x g ( f ( x ) ) = x , f−1(x)=x2−1 f - 1 ( x ) = x 2 - 1 is the inverse of f(x)=2x+2 f ( x ) = 2 x + 2 .

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

can you complete your sentence? i could !