What is the slop of a vertical line?

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Step-by-step explanation:

The slope of a vertical line ( line that goes up and down)

The y value changes but the x value does not

m = (y2-y1)/(x2-x1)

   = (y2-y1)/ (x-x)

   = (y2-y1)/0

Anything divided by 0 is undefined

D

Step-by-step explanation:

It's undefined. x = 5 means that every x value is 5. How does that happen?  What value of m will leave only x so that x = b?

Undefined is the only way that would happen. The y value is divided by infinity for a slope which leaves 0 on that side.

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