They always said algebra was another language. Write it just as you read it.
"half of the 7th graders" = 1/2 x s
"one third of the 8th graders" = 1/3 x e
"divided into 10 teams" = put everything over the denominator of 10
final answer=

5. 3g/10 + 25f
6. (3e - 4) + (2w + 6)
Hope this helps!