Answer:
[tex]x = -6[/tex]
Step-by-step explanation:
[tex]18 = [(-2) + (-1)]x[/tex]
Required
Find x
Remove the inner brackets
[tex]18 = [-2-1]x[/tex]
[tex]18 = [-3]x[/tex]
Remove the square bracket
[tex]18 = -3x[/tex]
Divide both sides by -3
[tex]\frac{18}{-3} = x[/tex]
[tex]x = -6[/tex]