Answer: -2
Step-by-step explanation:
Let the number be x , then twice the number is 2x.
Twelve decreased by twice the number = 12 - ( 2x )
8 times the sum of the number and 4 = 8 ( x + 4 )
combining the two , we have
12 - 2x = 8 ( x + 4 )
12 - 2x = 8x + 32
12 - 32 = 8x + 2x
-20 = 10x
x = -20/10
x = -2