tolong jawab pertanyaanku ya!!

2.

a. - 3m + 4n - 6 + 7n - 8m + 10
=>> - 3m - 8m + 4n + 7n - 6 + 10
=>> - 11 m + 11 n - 16

b. 15a + 7b - 5c + - 11a - 12b + 13d
=>> 15a + - 11a + 7b - 12b - 5c + 13 d
=>> 4a + 19b - 5c + 13 d

3.

a.