1) 2(4a + 3b) + 7(4b + a) = 8a + 6b + 28b + 7a = 15a + 34b
2) 3a + 8b - 4b + 3a - a = 6a + 4b
3) 12z + c + 21c - 7z - 4c + 43z - 10c + 4z = 48z - 7z + c + 21c - 4c - 10c - 4c = 36z + 8c
1) 2(4a + 3b) + 7(4b + a) = 8a + 6b + 28b + 7a = 15a + 34b
2) 3a + 8b - 4b + 3a - a = 6a + 4b
3) 12z + c + 21c - 7z - 4c + 43z - 10c + 4z = 48z - 7z + c + 21c - 4c - 10c - 4c = 36z + 8c