Answer:
options 1,3,4 are functions.
Step-by-step explanation:
RULE: a relation is said to be a function if every element in the domain ( the numbers in the left side in the below sets) is related to only one number ( number on the right side in the below sets).
Let us check each option one by one:
1.   3           2
     9           1
    -4           7
     0          -2
here each number on the left side is mapped to or is related to one number only.
so this relation is a function
2.  7         1
     -5        2,3
      1         0
 here, "-5" is mapped to two different numbers. so this relation is not a function.
3.  -2    -4
     2      4
     6      8
     -6    -8
here each number on the left side is mapped to or is related to one number only.
so this relation is a function
4.  1     3
    -1    3
    2    3
   -2    3
here each number on the left side is mapped to or is related to one number only.
so this relation is a function.
even if it is related to the same number, it doesn't matter.
it should follow the above given rule that's it.
 
        
             
        
        
        
Answer:
16
Step-by-step explanation:
Multiply by the scale factor, in this case 3/1 or just 3
 
        
             
        
        
        
The exact form is: w = -6/7