SOLUTION: Could someone please help me with a couple of problems,that I'm having trouble with? These are Systems of equations,and they need to be solved by the Elimination method.Also could

Question 145138: Could someone please help me with a couple of problems,that I'm having trouble with? These are Systems of equations,and they need to be solved by the Elimination method.Also could you show me how to work them step by step? Thank you very much in advance for your time and all the help.
1)5x - y = 12
3x + y = 4
2)2x - y = -6
2x - 2y = -4
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
This site has a good explanation of the "elimination method":
http://www.purplemath.com/modules/systlin6.htm
1)5x - y = 12
3x + y = 4
------------ start by adding both equations together to get rid of the 'y'
8x = 16
x = 2 (dividing both sides by 8)
To find y, substitute x back into either of the two equations:
5x - y = 12
5(2) - y = 12
10 - y = 12
-y = 2
y = -2
2)2x - y = -6
2x - 2y = -4

multiply the second equation by -1 to get:
2)2x - y = -6
-2x + 2y = 4
------------- add both equations together
y = -2
To find x, substitute y back into either of the two equations:
2x - y = -6
2x - (-2) = -6
2x + 2 = -6
2x = -8
x = -4

RELATED QUESTIONS
Solve the systems by graphing the following equations: 2x - y = 4 2x - y = 6 I am... (answered by stanbon)

Could you please help me with a couple of problems?These are systems of equations... (answered by checkley77)

Could someone please help me with a few problems?These are Systems of equations,and these (answered by algebrapro18)

could you please help me with a couple of problems? These are systems of equations(2 by... (answered by stanbon)

Tutor, I only have a couple of problems left that I am having trouble with could you... (answered by stanbon)

I'm still having trouble with the graph method.Could someone please show me how to do a... (answered by jim_thompson5910)

I am having trouble with writing out the equations that are in word form. Please help me. (answered by josmiceli,bucky)

Hello, I am having trouble answering two questions on projectiles using formulas: d=16t^2 (answered by solver91311,ikleyn,josmiceli)

I am having trouble with the addition and multiplication principles of solving... (answered by Earlsdon)