Well I don't know what you mean, but I might see it as this: 2(x+2) + 2(y +1)
= 2x + 4 + 2y + 2
= 2x + 2y + 6
This is a simple subtraction problem. Since she wants to buy something that costs 1000 with 2000 dollars you have to subtract 1000 from 2000. So, 2000-1000=1000
