SOLUTION: The question is: Solve each system by elimination. x-y=11 2x+y=19 How do I do this? In dummy language please. I want to actually understand what it is I'm suppose to be doi

Algebra ->  Linear-equations -> SOLUTION: The question is: Solve each system by elimination. x-y=11 2x+y=19 How do I do this? In dummy language please. I want to actually understand what it is I'm suppose to be doi      Log On


   

Question 469698: The question is: Solve each system by elimination.
x-y=11
2x+y=19
How do I do this? In dummy language please. I want to actually understand what it is I'm suppose to be doing. Thanks much!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Solve each system by elimination.
Just add the two equations, this will eliminate y, leaving x
x - y = 11
2x+ y = 19
-------------
3x + 0 = 30
3x = 30
divide both sides by 3
1x = 30%2F3
x = 10
:
Use the 2nd equation to find y
2x + y = 19
Replace x with 10
2(10) + y = 19
20 + y = 19
subtract 20 from each side
y = 19 - 20
y = -1
:
The solutions: x = 10, y = -1
:
:
Check this using the 1st equation
x - y = 11
Replace x with 10 and y with -1, see if it is true
10 - (-1) = 11
minus a minus is a plus, therefore
10 + 1 = 11; confirms our solution