Solving:
1)
-58 - 6x = 42 + 4x
Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
- 6x - 4x = 42 + 58
- 10x = 100 simplify by (-1)
10x = - 100
![x = \frac{-100}{10}](/tpl/images/0368/3948/2835a.png)
![\boxed{x = - 10}](/tpl/images/0368/3948/67e6e.png)
2)
37 + 5x = -2x - 33
Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
5x + 2x = - 33 - 37
7x = - 70
![x = \frac{-70}{7}](/tpl/images/0368/3948/f6077.png)
![\boxed{x = - 10}](/tpl/images/0368/3948/67e6e.png)
3)
27 - 9x = -6x - 39
Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
- 9x + 6x = - 39 - 27
- 3x = - 66 simplify by (-1)
3x = 66
![x = \frac{66}{3}](/tpl/images/0368/3948/54c6d.png)
![\boxed{x = 22}](/tpl/images/0368/3948/d9bcf.png)