What is the value of x in the solution to the following system of equations?

x − y = −3
x + 3y = 5

Question

What is the value of x in the solution to the following system of equations?

x − y = −3
x + 3y = 5

anonymous · Answer

help me pleas ill medal and fan

anonymous · Answer

Dude, just go to WolframAlpha.com...

anonymous · Answer

y = x + 3

campbell_st · Answer

triple the 1st equation then add it to the 2nd equation, that will eliminate y

does that make sense

anonymous · Answer

y = x

anonymous · Answer

so if i do that it would be 3

anonymous · Answer

@campbell_st

anonymous · Answer

Is my profile picture ugly?

michele_laino · Answer

please subtract the second equation from the first one

campbell_st · Answer

triple every term... is like multiplying every term by 3

    3x - 3y = -9
+   x  + 3y = 5
--------------


what add the 2 equations  -3y + 3y = 0   so y is eliminated

anonymous · Answer

oh i get it

campbell_st · Answer

so what do you get as the next step

jagr2713 · Answer

@OpiGeode what do you learn when u go on WolframAlpha and or other sites like it?

anonymous · Answer

wait so now we are solving for x right

anonymous · Answer

Basically you type in a math problem and it tells you how to solve it and gives you answer along with it.

jagr2713 · Answer

you have to pay for it to give you step by step solutions.

anonymous · Answer

No..

campbell_st · Answer

no... before you solve.... just add the 2 equations..... y will disappear... because -3y + 3y = 0

so what is 3x + x  = ?

and also -9 + 5 = ?

jagr2713 · Answer

Yes you do...

anonymous · Answer

-9 + 5 = 3

campbell_st · Answer

well not quite, can you 

-9 + 5 = 4

what about 3x + x =

campbell_st · Answer

dang.... -9 + 5 = -4

anonymous · Answer

oh ok i thought it was -8 minus 5 i didnt see it right

campbell_st · Answer

so   what about the 3x + x = ?

anonymous · Answer

you have too bring down the 3 right

campbell_st · Answer

no its 3x + 1x = ?x      what is the value of ?

anonymous · Answer

so its 4

anonymous · Answer

@campbell_st

campbell_st · Answer

great so the problem sets up as

    3x - 3y = -9
+   x  + 3y = 5
--------------
     4x = -4

now solve for x

anonymous · Answer

-1

campbell_st · Answer

great, that's it x = -1

all you need to do

anonymous · Answer

thank you so much

radar · Answer

You do know that you can subtract as well in the "elimination" process.
This is a case where you could just subtract the bottom equation from the top equation thus eliminating the "x" with a result of: -4y = -8   solving for y getting y=2