I'm not sure there is a single symbol you can use but you can do it like this.
5<x and x<9
Combine them ................ 5<x<9
5>x<9
A square root sign.
Decimal point
It depends. If you start with a positive number, then multiply by a positive greater than one and the answer is greater; multiply by 1 and the answer is the same; multiply by a number between 0 and 1 and the answer is smaller; multiply by 0 and the answer is 0; multiply by a number less than 0 and the answer is negative.
Greater than 100% or smaller than -100%.
5>9
Decimal point
The mathematical symbol you're thinking of is the "decimal point" or simply the "dot." When placed between 5 and 9, it is used to represent a decimal number that is greater than 5 and smaller than 9. For example, if you have 5.7, it's greater than 5 but less than 9.
A point.
A point.
5>x<9
A square root sign.
6
Decimal point
. (6<6.7<7)
a decimal point so the answer is 5.9
Any number from 25000001 to 54999999 is smaller than 55000000 but greater than 25000000.