A number increased by 4 is the same as 19 minus 2 time the number

Let's write it down in terms of maths:

A number increased by 4

this is x+4

is the same as 19 minus 2 time the number

this is = 19-2x

where x is "the number".

so:

x+4=19-2x

let's move x to one side:

3x=19-4

3x=15

divide by 3:

x=5

so the number is 5!