Five times a number , subtracted from twenty ,is triple the number. find the number .

Let's label the number you're trying to find x. You have to set up a system of equations.

1. Five times a number can be labeled as 5x.

2. Subtracted from 20 gives us 5x-20.

3. The problem says this is the same as simply tripling the original number. So set the first equation equal to 3x.

4. 5x-20=3x

5. Move like terms onto the same side. We can do this by subtracting 3x from both sides and adding 20 to both sides.

6. 5x-3x=20

7. 2x=20

8. Divide both sides by 2 to get x by itself.

x=10