I have 2 Algebra Questions?

Question

More ugly math review:

Is the value of one half of (1/a + 1/b) = 2/(a+b) or (a+b)/2???

Another question: 5n/3 + n/4

Answer 1

Wendy C Hi !!

1/2(1/a + 1/b)

=> 1/2a + 1/2b

=> b/2ab + a/2ab

=> 1/2ab(a + b)

=> (a + b)/2ab ← ans

5n/3 + n/4

factor out n

=> n(5/3 + 1/4)

=> n(5(4)/12 + 3/12)

=> n(20/12 + 3/12)

=> n(23/12) ← ans

hope this helps

Answer 2

1/a  +  1/b  has a least common denominator of ab.

So b/ab + a/ab = (a + b) / ab

One half of that = (a + b) / 2ab   <<<<<

That answer is not one of your choices, but it is correct.

--------------------------------------...

As to problem (2)  the least common denominator is 12.  so we get:

(4 x 5n) / 12 + [(3 x n) / (12)   This is equal to

20n + 3n

-------------

12

= 23n

----------   <<<<<

....12

Answer 3

1/2 X (1/a + 1/b) = 1/2a + 1/2b

1/2a X b/b + 1/2b X a/a

1b/2ab + 1a/2ab

(a+b)/2ab

(a+b)/2ab is your answer. It's neither of the two you have listed.

5n/3 + n/4

20n/12 + 3n/12 (We find a common domination so we can add them)

23n/12             (Add them)

And that gives you 23n/12 as your answer.

Hope this helps!