Answer: Yes; you do combine "-w" and "4w" ; because they are both "like terms" ; that is, they are both terms with the SAME first degree single variable in the entire expression.
So, to combine them:
-w + 4w = -1w + 4w = 3w ;
and we can simplify the entire expression:
" -w + 4w + 12 " ;
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to: " 3w + 12 " .
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Hope this explanation helps!
