499к+к

When you're adding the variable "к" to the number with the variable like "499к", you simply add the coefficients (numerical values) together, since they have the same variable:

499к + к

Since there's no numerical coefficient written in front of the second "к", it is understood to be 1. So, the equation is equivalent to:

499к + 1к

Combining like terms (adding the coefficients), we get:

(499 + 1)к

500к

So, 499к + к equals 500к.