If you expand the square, you have

Simplify the right hand side:

Cancel the -3x appearing on both sides:

Multiply both sides by 4:

Consider the square root of both terms (using the doubles sign):

Answer:
9+x<12
Step-by-step explanation:
add 9 to an unknown number.
9+x
use the < less than symbol (instead of an equal sign) and write 12.
Maybe 11x? i dont really know, thats all the info we get
The greatest number common to 50 and 10 is 10
10 is the answer
hope this helps