A taxi costs 3 dollars plus an additional 2 dollars per mile traveled \. You spent exactly $20 on taxi which includes the one dollar tip you left. How many miles did you travel?

8 miles

Step-by-step explanation:

The equation for this relationship is:

3+2x=y (x is no. of miles and y is the total cost without tips of course)

The total cost without the tip is 20-1=19.

Plug 19 in for y:

3+2x=19

2x=16

x=8

Hope this helps!

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