Answer:
21 = 6 - x - 4x
simplify 6-x-4x to 6-5x
21 = 6-5x
subtract 6 from both sides
21-6 = -5x
simplify 21 - 6 to 15
15 = -5x
divide both sides by -5
[tex]\frac{-15}{5}[/tex] = x
simplify [tex]\frac{15}{5}[/tex] to 3
-3 = x
switch sides
x = -3
Step-by-step explanation:
