1.75w + 6.45y
First subtract 1.25w from 3w
3w-1.25w=1.75w
Finally add 4.45y and 2y
4.45y+2y=6.45y
Your answer is 1.75w+6.45y
You cannot add two different variables like these two unless you know what they are equal to, so this is the simplest answer you can get.