Answer/Step-by-step explanation:
3. Function: NO
Justification: there will be more than one y-value/output related to one x-value/input.
4. Function: YES
Justification: There are exactly one y-value/output related to each input/x-value in the relation.
5. Function: YES
Justification: each x-value/input is mapped to exactly one y-value/output. No input value is mapped to more than one output value.
Answer:

Domain: 
Step-by-step explanation:
Given

Required
Determine f(x) and its domain
To determine f(x), we replace 5x with x in f(5x)
So, we have:


Take LCM



To get the domain, we set the denominator as



Answer:
7.5 should be the answer sorry if its wrong i don't have all of the information
X + (-2) = 4...
do the inverse +2 on both sides 4+2 equals 6. X= 6