It's a simple linear equation in the variable 'x'.
There's only one number that 'x' can be. If it's
any other number, then the equation is not true.
Here's how to find out what number 'x' must be:
The equation is ==> 2x + 5 = 4x
Subtract 2x from each side: 5 = 2x
Divide each side by 2 : 2.5 = x
