In order to solve this problem, you need to understand the concept of the zero vector.

It's difficult to understand his explanation.

This concept is difficult.

It took him a long time to solve the math problem.

He untied his shoelaces.

This game is considered a zero-sum game.

Understanding vector fields is an important concept in physics.

A vector product is an operation that generates a new vector from two vectors.

The balance of his bank account is zero.

It's difficult to understand his explanation.