Answer:
1217
Step-by-step explanation:
Given
[tex]Subjects = 2353[/tex]
[tex]Improvement = 1136[/tex]
Required
The number that didn't improve --- missing from the question.
Let the unimproved be represented as x.
So, we have:
[tex]x + Improvement = Subjects[/tex]
Substitute known values
[tex]x + 1136 = 2353[/tex]
Solve for x
[tex]x =- 1136 + 2353[/tex]
[tex]x =1217[/tex]