Question

Add.

3/w+4 + 4/5w

would the answer be 7/4+5w?

Answer 1

No. What is the common denominator?

Answer 2

I think it would be 20 right?

Answer 3

nope. 20 is not the common denominator,,

on the given, i think you mean 3/(w+4) + 4/5w ,,
first thing, multiply BOTH the numerator and denominator of the terms with their common denominator, which is (w+4)(5w),, therefore,
(3/(w+4) + 4/5w)*(5w)(w+4)/(5w)(w+4) ==> some terms will cancel out, leading to
(3(5w) + 4(w+4))/(w+4)(5w)
simplifying, you will get:
(19w+16)/(5w^2+20w)

note: the multiplier (5w)(w+4)/(5w)(w+4) is equal to one, and therefore will not alter the original given,, =)

*another alternative would be to use cross-multiplication,, you will get the same answer after simplifying,, =)