The elevation of New Orleans, Louisiana is on average 8 feet below sea level. The elevation of El Centro, California is 39 feet below sea level. What is the difference in elevation between the two cities? A 31 ft
B -31 ft
C 47 ft
D -47 ft

a

explanation:

what is

step-by-step explanation:

1 and 0

step-by-step explanation:

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