A bookcase has 5 of these bookshelves that are 42 inches long. How many FEET of shelf space is there? Explain your reasoning. (If the answer is given in inches you can only get a 4 out of 6 maximum. How many FEET of shelf space is the answer you explain.) *

Step-by-step explanation:

A bookcase has 5 bookshelves. Each bookshelf is 42 inches long.

Total bookshelf length in the book case =

The bookcase has a total shelf space of .

*One bookshelf has a space of .

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