can anyone exsplain how you would use the elimination method to solve these equations
1) 5x + 2y = 5
&
2) 3x - 4y = -23

Question

can anyone exsplain how you would use the elimination method to solve these equations 
1) 5x + 2y = 5
& 
2) 3x - 4y = -23

radar · Answer

Which variable do you wish to eliminate, x or y?  Your choice.

radar · Answer

I personally would choose y, but you may prefer x.  Which one.....choose so we can start!

anonymous · Answer

lets do Y!

radar · Answer

Good choice, but x would of been ok also.
Y it is, we must get the coefficient of y on one equation to equal the coefficient of y in the other equation.   We must ultimately have equal coefficients for y.

radar · Answer

To do that, we will multiply the first equation by 2.   Getting:10x+4y=10
Note that we now have 4 for the coefficient of y in both equations.  Do you follow with understanding?

anonymous · Answer

i do

radar · Answer

10x+4y = 10
3x - 4y  =-23

radar · Answer

These are the two equations that we will use to eliminate Y    All we have to do is to add those two equations and the Y will just disappear (have a 0 coefficient)

anonymous · Answer

alright!

radar · Answer

Adding them I get 13x=-13     so x = -1

radar · Answer

Now substitute the -1 for x on one of the original equations and solve for Y.  Now ur good.

anonymous · Answer

so id take x and use -1 on 10x ? like this 10 -1  = 9?

radar · Answer

I would take the original equation 5x+2y=5    (you could of used the other one just as well) 
Now substisute the value found for x  (the -1) getting: 5(-1) + 2y =5   using algebra to solve:
-5 +2y = 5
2y=10
y=5
the answer is y=5, it should work also with the second equation.

radar · Answer

Just to confirm. 3x-4y=-23
3(-1)-4y=-23
-3-4y=-23
-4y=-20
y=5       as you see it works, it is a good answer.

anonymous · Answer

wow thanks a ton man.  helped alot.

radar · Answer

Summarizing:
1.  Select a variable to eliminate.
2.  Multiply or divide the equation to obtain equal coefficients (if they are opposite sign OK)
3.  Add or subtract the two equations to eliminate the coefficients (if sign are opposite add, if they are same subtract)
4.  Solve for remaining variable
5.  substitute new found value into original equation and solve for other variable.

radar · Answer

@Luis Rivera  what is that about???