Math Question........?

Question

When you double a number and add five, the result is three less than twice the number. What is the number?

this is no trick question. it came right out of my math book. i myself don't know the answer.

Answer 1

When you double a number and add 5:

2x + 5

The result is 3 less than twice the number:

= 2x - 3

2x + 5 = 2x - 3

Subtract 2x from both sides:

5 = -3

This means that's it's impossible. There is no number that, when you double it and add 5 gets the same result as when you double it and subtract 3 (which makes sense).

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Mark Anthony found an answer, but it's wrong, unless you meant to say:

"the result is three, less twice the number." (i.e. 3 - 2x)

As it is I stick by my answer.

Answer 2

There is no such number. Doubling a number is the same thing as twice a number.
Your equation would be
2x + 5 = 2x - 3
5 = -3
This is not true.

Answer 3

Lol, no point adding more to what's said.

But really:

twice a number=twice a number=X (for the heck of it)

X ADD FIVE cannot equal X MINUS THREE

Answer 4

There is no such number!

Let x represent the number.

2x + 5 = 2x - 3

2x - 2x = -3 -5
0x = -8

This is impossible as -8/0 is undefined.

So either check the question again...or it was a trick question :)

Answer 5

2x + 5 = 2x - 3
5 /= -3

All of the x terms cancel so there is no number that fits this description.

Answer 6

2x+5 = 3-2x
4x = -2
x = -1/2