Twelve decreased by twice a number is the same as 8 times the sum of the number and 4. What is the number.

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