Раскройте скобки и n-(n-(11n-7)) -3m)+9x) 13d-(8d-(13d-(4d+ 3f-(-4f)12u))

1. n-(n-(11n-7))
n-(n-11n+7)
n-n+11n-7
11n-7
2. 4m-((7x-3m)+9x)
4m-(7x-3m+9x)
4m-7x+3m-9x
7m-16x
3. 13d-(8d-(13d-(4d+9)))
13d-(8d-(13d-4d-9))
13d-(8d-13d+4d+9)
13d-8d+13d-4d-9
14d-9
4. 3f-(3f-((u-4f)12u)) тут скорее всего опечатка. Возможно два случая:
а) 3f-(3f-((u-4f)+12u))
3f-(3f-(u-4f+12u))
3f-(3f-u+4f-12u)
3f-3f+u-4f+12u
-4f+13u
б) 3f-(3f-((u-4f)-12u))
3f-(3f-(u-4f-12u))
3f-(3f-u+4f+12u)
3f-3f+u-4f-12u
-4f-11u