Answer:
9
Step-by-step explanation:
First, find <em>x</em>. Since <em>x</em> is the average of the three number, add the three up and then divided by three. Thus:

<em>y</em> is the cube root of 8. Thus:
![y=\sqrt[3]{8}=2](https://tex.z-dn.net/?f=y%3D%5Csqrt%5B3%5D%7B8%7D%3D2)
So:

Answer: 64 25% of 256 is 64
Step-by-step explanation:
18. S=r^2-t^2
S+t^2=r^2
r=sqrt(S+t^2)
20. Tan 18=x/12
x=12×Tan 18
x=3.899036355
x=3.90
I hope this helps.