Which statement describes the graph and system of equations?
3y-x=12
x-3y=6

A. coincident
B. consistent and independent
C. inconsistent
D. not enough info

Question

Which statement describes the graph and system of equations?
3y-x=12
x-3y=6


A. coincident
B. consistent and independent
C. inconsistent 
D. not enough info

itsbribro · Answer

@kah.x  @Destinyyyy @whpalmer4 @Agl202

itsbribro · Answer

i cant post the graph.
it won't let me

agl202 · Answer

Is this what ur graph looks like? http://assets.openstudy.com/updates/attachments/52c5b6e6e4b0b729fb8cbb6f-wildberries-1388689159624-help.jpg

itsbribro · Answer

yes

agl202 · Answer

I would say it is B. consistent and independent. 
Points that work in each equation...consistent. When a system is "dependent," it means that all points that work in. One of them also work in the other one. Graphically, this means that. One line is lying entirely on top of the other one, so that if you graphed both, you would really see only one line on the graph. Since they are imposed on top of each other. One of them totally depends on the other one. So, B. is what I say.

itsbribro · Answer

ohhhhh okay now i kinda understand lol

itsbribro · Answer

i think its inconsistent :/

itsbribro · Answer

but thank you for your help :) i appreciate it

whpalmer4 · Answer

This is an inconsistent system of equations.

To quote the wikipedia article on systems of linear equations:
A linear system is inconsistent if it has no solution, and otherwise it is said to be consistent. When the system is inconsistent, it is possible to derive a contradiction from the equations, that may always be rewritten such as the statement 0 = 1.

$$3y-x=12$$$$x-3y=6$$
Look what happens if we solve the second equation for $x$ and substitute that into the first:

$$x-3y=6$$$$x=3y+6$$$$3y-x=12$$$$3y-(3y+6)=12$$$$3y-3y-6=12$$$$-6=12$$