5x+15+2x=24+4x
its so simple
First arrange the numbers & alpha nurmeruc in sequence
Now your equation become
5x+2x-4x = 24-15
When ever you change place of any number or alpha numeric beyond equallity the sign that number or alpha numeric contains just reverse.
After simplifying
7x-4x = 9
3x = 9
x = 9/3
x = 3