Answer:
3). r = -1
4).n = 2
5). x = 1
6). n = 5
Explanation:
3).
8r + 6 + 4r = -6
12r + 6 = -6
12r = -6 - 6
12r = -12
r = -12/12
r = -1
4).
1 - 5n - 4n = -17
1 - 9n = -17
-9n = -17 - 1
-9n = -18
n = -18/-9
n = 2
5).
4 = -5 + 2x + 7
4 = 2x + 2
4 - 2 = 2x
2 = 2x
2/2 = x
1 = x
6).
-4n + 8n = 20
4n = 20
n = 20/4
n = 5
