tolong di jawab ya, yg udh jawab mksih

Mapel : Matematika
Bab : Aljabar

A) -3m + 4n - 6 + (7n - 8m + 10)
   = -3m + 4n - 6 + 7n - 8m + 10
   = -3m - 8m + 4n + 7n - 6 + 10
   = -11m + 11n + 4

B) 15a + 7b - 5c + (-11a - 12b + 13d)
   = 15a + 7b - 5c - 11a - 12b + 13d
   = 15a - 11a + 7b - 12b - 5c + 13d
   = 4a - 5b - 5c + 13d

a. -3m+4n-6 +(7n-8m+10)
-3m-8m+4n+7n-6+10
-11m +11n+4

b. 15a+7b-5c +(-11a-12b+13d)
15a-11a+7b-12b-5c+13d
4a-5b-5c+13d

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