A "roster" here is essentially a version of the set with all of elements listed out. Here, those elements are all of the odd numbers between 20 and 30, so our list would be
{21, 23, 25, 27, 29}
To complete the square you must split the b term in half, then square that answer.
6 is the b term, half of 6 is 3, 3 squared is 9. You will add 9 to both sides of x^2 + 6x = 15
x^2 + 6x + 9 = 24
You'll have to subtract 5 on each side and that'll leave 3 ≥ 3x
Then you'll divide on both sides and flip the inequality: x ≤ 1
There’s gotta be an attachment