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21 votes
if the sum of a number and seven is doubled, the result is eight less than the number. Find the number

2 Answers

5 votes

Answer:

-22

Explanation:

The result is eight less than the number means that

the result = number - 8

( x + 7 ) * 2 = x - 8

=> 2x + 14 = x - 8

=> x = -22

User Ravi Sankar Raju
by
4.7k points
6 votes

Answer: -18

Explanation:

Let the number be represented by x.

If the sum of a number and seven is doubled, the result is four less than the number. The expression would be

2(x + 7) = x - 4

We would open the bracket on the left hand side of the equation by multiplying each term inside the bracket by 2. It becomes

2x + 14 = x - 4

Subtracting 14 and x from the left hand side and the right hand side of the equation, it becomes

2x + 14 - 14 - x =x - x - 4 - 14

x = - 18

User JohnyFree
by
5.3k points