What is an open sentence

The video tutorial explains the concept of open sentences in mathematics. It begins by discussing equations as mathematical sentences that are true when both sides are equal. The introduction of variables like X and Y makes it unclear if an equation is true or false, leading to the concept of open sentences. Open sentences are equations with variables whose truth depends on the values of these variables. The video provides examples to illustrate how open sentences work, emphasizing that they remain 'open' until specific values are assigned to the variables.

Explain the significance of the equality sign in an equation.

What makes an equation true or false when variables are involved?