Five added to 2 times a number is equal to 7 less than 4 times the number

Let the number be X.

2X + 5 = 4X - 7
Therefore 4X - 7 = 2X + 5

Now all of the Xs need to be on one side:

4X - 7 - 2X = 5
2X - 7 = 5

Now put the single numbers all on the other side:

2X = 5 + 7
2X = 12

And finally divide by the number in front of the X:

2X / 2 = 12 / 2
X = 6

So the original number is 6.