1) 8x = -16
x = -16/8
x = -2

2) -25x = 10
x = 10/(-25)
x = -0.4

3) 2x = 0.64
x = 0.64/2
x = 0.32

4) 0.3x = -2.7
x = -2.7/0.3
x = -9

5) -2/5x = 3/10
x = (3/10) / (-2/5)
x = (3/10) * (-5/2)
x = -15/20
x = -3/4

6) 8x - 5 = x - 40
8x - x = -40 + 5
7x = -35
x = -35/7
x = -5

7) 7x + 21 = x - 3
7x - x = -3 - 21
6x = -24
x = -24/6
x = -4

8) 0.3x - 5 = 6 - 0.7x
0.3x + 0.7x = 6 + 5
1x = 11
x = 11

9) 3x + 5 = 5x + 13
3x - 5x = 13 - 5
-2x = 8
x = 8/-2
x = -4