Question

sum of twice a number and 5 lies between 7 and 11

Here is how you would write that:
7 < 2x +5 < 11

You can subtract 5 from each term and divide each term by 2 while keeping the < signs in the same direction. This results in
2 < 2x < 6, and then
1 < x < 3

What symbols are used for the phrases
at least
no less than
no greater than

Thank you