As 15 more people can go on with 2/3 of x already on, to make the value of x, this can be written as an expression like so:
[tex]\frac{2}{3}x + 15 = x[/tex]
You can rearrange the equation like so to get the final answer:
[tex]15 = x - \frac{2}{3}x[/tex]
[tex]15 = \frac{1}{3}x[/tex]
[tex]15 * 3 = x[/tex]
[tex]x = 45[/tex]
Hope this helps :)
