SOLUTION: I cant figure out this word problem: Five times a number is 21 less than twice the opposite of the number. What is the number?

Question 65022: I cant figure out this word problem: Five times a number is 21 less than twice the opposite of the number. What is the number?
Answer by 303795(602) (Show Source): You can put this solution on YOUR website!
Call the required number x.
Five times the number is 5x.
If this is 21 less than something then add on 21 so it will be equal to it.
5x + 21 =
The opposite of the number is (-x). Twice that will be 2*(-x)
So 5x + 21 = 2*(-x)

5x + 21 = -2x
Add 2x to both sides of the equation
5x + 26 + 2x = -2x + 2x
7x + 21 = 0
Subtract 21 from each side of the equation
7x + 21 - 21 = 0 - 21
7x = -21
x=-21/7
x=-3
Check if this meets the original conditions.
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