How come it’s a right triangle, I think you do a2+b2=C2. Therefore, you do 9.4 times 9.4 and then 15.1 times 15.1. So it will be 9.4 + b2=15.1. 88.36+ b2=228.01. Then you subtract that and it will be 139.65. Then you do square roots because you are trying to get rid of the second power. And the final answer is 11.81736011. How they told you to round it to the nearest tenth, I will be 11.8. I think this is the answer.
Solving for part A

Domain of composition: x ≠ 0 i.e. Domain is the set of "Real numbers excluding number 0".
Solving for part B

Answer:
Step-by-step explanation:
Each of the values in the given ratio is a multiple of 6. It can be reduced to lowest terms by dividing by 6. Then equivalents can be formed by multiplying the basic ratio by any number of your choice
36:42 = 6:7
= 12:14 . . . . . . . multiply by 2
= 18:21 . . . . . . . multiply by 3
= 24:28 . . . . . . multiply by 4
= 96:112 . . . . . . multiply by 16