4. k less than 3.5, so a number k is being taken away from 3.5:
The answer is 3.5-k
5. the sum of g and h, reduced by 11, so you need a set of parentheses to write this one: (g+h)-11
6. 5 less than y, plus g, so do a combination of the strategies used in the previous two problems and you will get: (y-5)+g
7. 5 less than the sum of y and g, you are taking away 5 from the sum of two numbers, y and g, so: (y+g)-5
Hope this helps :-)