Answer:
x = 4
Step-by-step explanation:
Given
=
( cross- multiply )
3x = 12 ( divide both sides by 3 )
x = 4
For it to be non-linear, the rate of change cannot be constant. For the first table the rate is a constant 1 and the second table has a constant rate of -1. The 3rd and 4th tables have no constant rate and thus are non-linear.
The 4th table is increasing while the 3rd table is decreasing.
So the 3rd table, Set C, is the only non-linear negative association between x and y.
Answer:
There are many. Two examples are

Step-by-step explanation:
There are many examples. The simplest is
1 -

It is trivial that

2 -

That function is injective as well.

An example of a function that is NOT injective is

Notice that
