For the first one, the answer is a.
Answer: 11.5
Step-by-step explanation:
15 + 2x = 42
-15 -15
----- -----
2x = 23
----- ------
2 2
x = 11.5
A= there are "4"one fourths in one hour and he hikes 2 miles every hour
B= 1, 1 1/2, 2, 4
C= it going to be 1/3 mile for every 1/6hour and she hikes 2 miles every hour.
D= 2/3, 1, 2, 4
Yes, it is a function.
One-to-one mappings and many-to-one can both be classified as functions;
One-to-many mappings are the only kind that can't be classified as functions.