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

Feb 21, 2018

#### Answer:

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:
$\left(- 1\right) \left(9 y - 9 x\right) = \left(- 27\right) \left(- 1\right) \implies - 9 y + 9 x = 27 \implies 9 x - 9 y = 27$
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]} *