Math for dummies?

Question

how do i find the equation of
a) a line
b)a prabola
c) a circle
from a graph
answer in standard form!
(no specific question just how to ...i kinda forgot...with examples if posible THANK YOU)

Answer 1

Line: y = ax + b. That covers everything except vertical lines.

ax + by = c covers all lines.

Parabola: y = ax^2 + by + c.

Circle -- I'm getting bored. Use google.