Answer:
because each output has exactly one input
Answer:

Step-by-step explanation:
We can add a line to create a triangle and a rectangle. The triangle will have side lengths 10 and 6. Furthermore, it will be a right triangle, meaning we can apply the Pythagorean Theorem to find x, the hypotenuse.

hope this helped! :)
1/3 + 1/7 = ?
7/21 + 3/21 = 10/21
The answer is 10/21.