Answer:
x=4
Explanation:
Simplifying 
-1(7 + -4x) = 9 
(7 * -1 + -4x * -1) = 9 
(-7 + 4x) = 9 
 
Solving 
-7 + 4x = 9 
 
Solving for variable 'x'. 
 
Move all terms containing x to the left, all other terms to the right. 
 
Add '7' to each side of the equation. 
-7 + 7 + 4x = 9 + 7 
 
Combine like terms: -7 + 7 = 0 
0 + 4x = 9 + 7 
4x = 9 + 7 
 
Combine like terms: 9 + 7 = 16 
4x = 16 
 
Divide each side by '4'. 
x = 4