It's a bit tedious, but it's just a bunch of factoring and manipulation.
Sh would have 20 pennies because for every 5 pennies there 4 quarters so , if she has 16 quarters she would have 20 pennies
Read this article https://weteachscience.org/mentoring/resources/lesson-plans/algebra-1-%E2%80%93-how-to-graph-a-linea...
Answer:
because they all have 3 corners