Question

- 4 x + 9 = 21 x=___ help

Answer 1

X=-3
because
-4x=21-9
-4x= 12 divide both sides
x=-3

Answer 2

Answer:

$- 4x + 9 = 21 \\ - 4x = 21 - 9 \\ = 12 \\ x = \frac{12}{ - 4} \\ x = - 3$