Let the marks of the students in class 1 be

the average of these 12 marks is 90, so

which means

similarly, let

be the marks of the students in the second class,
so

which means

The 32 students averaged:
The answer should be (7x=21).
Answer:
x<-3
Step-by-step explanation:
-7x+6/3 >9
-7x+6 >27
-7x>27-6
-7x>21
-x>3
x<-3