The operation $*$ is defined for non-zero $a$ and $b$ as follows: $a * b = \frac{1}{a} + \frac{1}{b}$. If $a+b = 13$ and $ a \times b = 25$, what is the value of $a*b$? Express your answer as a common fraction.
Since we know that a x b = 25, we can put 1/a + 1/b as (b + a) / 25.
Then we know that a + b = 13, so 1/a + 1/b would equal 13/25, which is your answer :)
Since we know that a x b = 25, we can put 1/a + 1/b as (b + a) / 25.
Then we know that a + b = 13, so 1/a + 1/b would equal 13/25, which is your answer :)