# Week 13 Day 1 Lesson Summary

Describe how you know if a system has **one** solution - both what it looks like on a graph and what you know about the equations.

Describe how you know if a system has **no** solution - both what it looks like on a graph and what you know about the equations.

Describe how you know if a system has **infinitely many** solutions - both what it looks like on a graph and what you know about the equations.