Solve x + 2y = 13
4x + 8y = -9

(3, 5)
(-1, 7)
No Solutions
Infinitely Many Solutions

Question

Solve x + 2y = 13
4x + 8y = -9
 	
	(3, 5)
	(-1, 7)
	No Solutions
	Infinitely Many Solutions

anonymous · Answer

So i already used elimination and got...
       x + 2y = 13
+   4x + 8y = -9
__________________________
 5x + 10y = 4

but i don't know what to do next.

anonymous · Answer

No, that's not right, for elimination to work, first you pick a variable to ELIMINATE, to do that you take the 2 equations and multiply it by numbers that will give you opposites, so lets say you want to eliminate x, multiply the first equation by -4, and the second by 1, does that make sense?

nincompoop · Answer

how is that exactly an elimination method?

nincompoop · Answer

the more appropriate question would be, what did you eliminate in that method?

anonymous · Answer

@iambatman ok i understand. so 

-4(x+2y) = 13  
do you multiplay 13 by -4 as well?

anonymous · Answer

Yes, the whole equation

nincompoop · Answer

his name is Bruce, btw

anonymous · Answer

Nin quit giving out my secret identity, you so phat.

wolf1728 · Answer

Bruce Wayne, the billionaire financier that donates generously to the charities of Gotham City?

anonymous · Answer

so when both the equations cancel out then what?
-4x - 8y = -52
4x + 8y = -9

anonymous · Answer

what is happening hahahahah

anonymous · Answer

@wolf1728 Yup, that's me ^.^

@kellyconnelly Yes, now add them just like the last problem so we can  eliminate the variables, and look and x and y, you notice anything?

anonymous · Answer

at*

anonymous · Answer

idk

anonymous · Answer

theyre zero?

anonymous · Answer

Yes, you get 0  = -61, meaning the answer is no solutions :)

anonymous · Answer

wow you're perfect

anonymous · Answer

http://38.media.tumblr.com/0b71e54827e7f300c7f573583a56cfdb/tumblr_n1iomp3Z1K1snwzimo1_400.gif haha

anonymous · Answer

thats exactly why

wolf1728 · Answer

and to give a serious answer here, if you were to graph the 2 equations, they would NEVER intersect indicating no solution.

anonymous · Answer

Yes, they would be parallel lines,

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wolf1728 · Answer

Hmmm, so does that mean the answer is 
No Solutions OR
Infinitely Many Solutions ?

anonymous · Answer

No solutions, only way I could see it being infinitely many solutions is if they are coincident lines.

wolf1728 · Answer

Okay, thanks.  I just wanted to make absolutely sure.

anonymous · Answer

Np ^.^

anonymous · Answer

Just an fyi, it would be infinite solutions if you got something like 0 = 0.