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

2+3+2=7
Red has 3
Yellow has 2
2+3=5
5/7 is the fraction of red or yellow marbles in the bag.
Doubling would not change the answer
Answer:
x=7
Step-by-step explanation:
because ther is 7 days in a week