Step-by-step explanation:

4 and 5
This is because when you multiply 6 by 4 you get 24. Then you divide it by 5 which is 4.8, the answer lies between 4 & 5.
Answer:
17
Step-by-step explanation:
because there are numbers involved
30-f+8f=30
30+7f=30
Move +30 to the right side. Sign changes from +30 to -30.
30-30+7f=30-30
7f=0
Divde by 7
7f/7=0/7
Cross out 7 and 7, divide by 7. Becomes 1*1*f=f
f=0
Answer: f=0