Раскройте скобки и упростите

n - (n - (11n-7))

4m - ((7x-3m) + 9x)

13d - (8d - (13d - (4d+9)))

3f - (3f - ((u-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