# Distinguishing extra element from two arrays?

## 1 Expert Answer

Tridip C. answered • 08/05/20

4+ years of Experience in Academic Research and Tutoring in Logic

Let's call the arrays **A** and **B** and let their unique elements be **a** and **b**, respectively.

First, take the sums of both arrays and subtract one from the other; since everything else cancels,

**sum(A) - sum(B) = a - b = s**.

Then, multiply the elements of both arrays and divide one by the other. Again, things cancel, so

**mult(A) / mult(B) = a / b = r**.

Now, from these, we get:

**a = rb**, so **rb - b = s** or **b = s / (r - 1)** and then **a = rs / (r - 1)**

## Still looking for help? Get the right answer, fast.

Get a free answer to a quick problem.

Most questions answered within 4 hours.

#### OR

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.

Patrick B.

07/13/19