1.) The sum lets you know its addition, a number could be anything we don't know and 8. we will let x represent any number ( you can use any expression) x+8
2.) 5 < x
3.) product lets you know its multiplication, again one is unknown and the other is 9.
you can write this like 9x or 9(x) or 9 x X
4.) this is the same as the one above, 4x or 4 x X (IF YOU DONT LIKE THE LETTER X YOU CAN USE ANY LETTER IT DOESNT MATTER like 4 x b)
5.) quotient means division: 18 divided by x or 18/x