Answer:
I'm gonna rewrite each sentence in a way that lines up a little more with the Algebraic expression you would end up with. Just keep in mind that either way of saying it is correct.
1. "8 times some number (a variable) minus 5"
8x-5
2. "13 plus some number"
13+x
3. "Some number over 7"
x/7 or x÷7
4. "d number of drinks times 3.50 plus 12 equals how much John spent (we'll call it J)"
12+3.50d = J
5. "Stacey bowled x number of games times the cost of one game (call it B) plus the cost of the shoes (call it P) which equals how much they spent (call it S)"
xB+P = S
6. "675.95 dollars was spent at the mall by a number of players (call it P) to equal the total cost per player)"
$675.95÷p (players) = 675.95/p (dollars/player)
Essentially you're making expressions or equations out of numbers you know and putting in variables as place holders for numbers you don't know. The variables can be whatever letters you like, but you'll want to write what each variable represents down nearby. Otherwise the reader/your teacher won't know what's what.