Question

How do you solve `9x-9y=27`, `9y-9x= -27` by graphing?

Answer 1

all the points that belong to the straight line 9x-9y=27

Explanation:

Solving a system mean finding the common solutions of the equations. Geometrically speaking that means finding the points they have in common on a Cartesian plane, in other words the solutions of a system are the point where the functions intercect.
In your case you have two equations that are the same.
In fact:
`(-1)(9y-9x)=(-27)(-1)=>-9y+9x=27=>9x-9y=27`
The two equations occupy the same points in the plane so the solution is
all the points that belong to the straight line 9x-9y=27
graph{9x-9y=27 [-10, 10, -5, 5]} graph{9y-9x=-27 [-10, 10, -5, 5]} *