During summer vacation, you charge people 8$ per hour for swimming lessons and 20$ registration fee. If you make 52$ one day, how many hours did you spend teaching lessons?

You taught for 4 hours

Step-by-step explanation:

Let this number of hours be x.  Then:

Total earned = $20 + ($8/hr)x

Equate this to $52 and then solve the resulting equation for x:

20 + 8x = 52

Then 8x = 32, and x = 4.  You taught for 4 hours.

Option B is correct.

The relation which has an inverse that is not a function is :(1, 2), (1, 3), (4, 3)

Step-by-step explanation:

Inverse of a function is the set of ordered pairs obtained by interchanging the first and second elements of each pair in the original function.

Let f(x) ={(1, 2), (1, 3), (4, 3)}

To find the inverse:

Inverse of f(x)=g(x)= {(2, 1), (3, 1), (3, 4)}

Function states that a relation in which each input value has only one output value.

Since, g(x) is not a function because the input 3 has multiple output values,.

Therefore, the only relation which has an inverse that is not a function is :(1, 2), (1, 3), (4, 3)