Answer:
In total 5,850 students do not favor this idea.
Step-by-step explanation:
Here, total number of students in the high school = 7,000
Total seniors in the school = 1/7 of total students
=

So, the school has total 1000 seniors.
Number of juniors in the school = Total Students - Number of seniors
= 7,000 - 1,000 = 6,000
So, the school has total 6,000 juniors.
Now, 2/5 of seniors are in favor of debate team.
2/5 of seniors =

So, 400 seniors are in FAVOR of the debate team.
Also, 1/8 of juniors are in favor of debate team.
1/8 of juniors =

So, 750 juniors are in FAVOR of the debate team.
⇒Total students favoring the debate team = 400 + 750 = 1150
Number of students NOT in favor = Total Students - Number of students in favor
= 7000 - 1150 = 5850
Hence, in total 5,850 students do not favor this idea.