You can not do the first one because the things do not add up
Six less the number n - 6= n/2
Answer:

Step-by-step explanation:
Simplify:


Group same factor:

Add :

Apply the distributive law: -(a+b) = -a - b


Group same factor:

Subtract:

Add:

Group same factor:

Hence answer = 
<u><em>~lenvy~</em></u>
Each are divisible by 11 so the ratio equivalent would be 7:9
The square root of Pi is approximately 1.77245.