Then I am stuck. I think the provided answer contains an error. But even if they are right, why does this last step equal f(x,y) + g(y) ???
Then I am stuck. I think the provided answer contains an error. But even if they are right, why does this last step equal f(x,y) + g(y) ???
Absolutely agree, lowk a programmer must’ve done it else I don’t think I’ve met a mathmematician (or maybe, not crazy enough ones) that ever preferred redefining variables (esp in pedagogical material!!!)