Question 64990
Hi lackinmath,
Still haven't changed your nickname, huh?
I am to use interval notation for the solution set:

3x+9=3(x-3)
3x+9=3x-9
3x-3x+9=3x-3x-9
0+9=0-9
9=-9  There is no solution.  They usually put this / over top of 0 to indicate that in interval notation.
:
Here is another one:
3x<9 and 2x+1>3
3x/3<9/3  and 2x+1-1>3-1
x<3 and 2x>2
x<3 and 2x/2>2/2
x<3 and x>1
"and"  means that x is both less than 3 and greater than 1.  X is between 3 and 1.
In interval notation: (1,3)
Happy Calculating!!!!
funmath