tolong donk kerjakn ini 1 dan 2

1. (15a + 7b - 5c) + (-11a - 12b + 13d) =
15a + 7b - 5c - 11a - 12b + 13d =
4a - 5b - 5c + 13d
2. (-3m + 4n - 6) - (7n - 8m + 10) =
-3m + 4n - 6 - 7n - 8m + 10 =
-11m - 3n +4

1. (15a+7b-5c)+(-11a-12b-13d)=
15a+7b-5c-11a-12b-13d = 15a-11a +7b-12b-5c-13d
= 4a-5b-5c-13d
2. (7n-8m+10)-(-3m+4n-6) =7n-8m+10+3m+4n-6
= 7n+4n-8m+3m+10-6
= 11n-5m+4