Answer:
13.7
Step-by-step explanation:
The computation of the volume of toy A is shown below:
7 × k^2=9
k^2= 9 ÷ 7
k=√9 ÷ 7
k = 1.133893419
Now
= 20 ÷ 1.133893419³
=13.7
1. Given (12+3)x, we can sum the numbers in the parenthesis to get 15x
2. Given 12x+3x, we can factor x to get (12+3)x and get the same as 1.
3. Given (12+3x)x, we have to distribute the x and we have 
4. This expression is already simplified.
|6k+12|=0
6k+12=0
K=12/6= -2 or 2
Its the transitive property. Transitive means that is a=b and b=c then a=c. It matches with what they're asking for.