How do you simplify (a^-1 + b^-1)^-1?

1 Answer
Jan 10, 2016

(ab)/(a+b)

Explanation:

The power of -1 means find the reciprocal (i.e. 1 divided by the value)

Write a^-1 as 1/a and b^-1 as 1/b

Then:
(1/a+1/b)^-1 = ((a+b)/(ab))^-1 = (ab)/(a+b)