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Twelve decreased by twice a number is the same as 8 times the sumof the number plus 4. What is the number?

2 Answers

3 votes
12-2x = 8(x+4)

12-2x = 8x+32

12-10x = 32

-10x = 20

x= -2
User Matthew Talbert
by
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5 votes

Answer: The number is -2


Explanation:

Let x be the number.

Then according to the question, we have the equation


12-2x=8(x+4)

First open parenthesis on the right side by multiplying 8 inside, we get
12-2x=8x+32

Now, Subtract 32 and add 2x from both sides we get


\\\Rightarrow\ 12-32=8x+2x\\\Rightarrow-20=10x\\\Rightarrow\ x=(-20)/(10)\\\Rightarrow\ x=-2

Hence the number is -2.

User DeeDub
by
4.7k points