There are a lot of expressions that can be considered "equivalent" to this one. Any algebraic expression, in fact, can have many other expressions that are equivalent.
However, you use the work "which" in your question, which makes it sound like this may have been a multiple choice question and you need to pick the right one.
In any case, the usual thing to do when you have two binomial terms being multiplied is just to multiply them out. That means multiply each value in the first term by each value in the second term and then add them together:
(w - 6) (w + 8)
w * w = w2
w * 8 = 8w
(-6) * w = -6w
(-6) * 8 =-48
So that gives you w2 + 8w - 6w - 48
You can combine the two terms with w to get w2 + 2w - 48. But you can't combine the w2 term or the -48 term with anything, so you have to leave them as is.