Question

What is 2x plus 5 equal 4x

Answer 1

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

Answer 2

2x+5=4x. 
Subtract 4x by 2x.
All you would have left is 5=2x
Divide 5 by 2x. 
You should get 2.5