Math
posted by Bonnie on .
Add.
3/w+4 + 4/5w
would the answer be 7/4+5w?

No. What is the common denominator?

I think it would be 20 right?

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 crossmultiplication,, you will get the same answer after simplifying,, =)