Question 616551: Explain the process of using elimination to solve a system of equations.
Answer by ladyluck4772(11)   (Show Source):
You can put this solution on YOUR website! You can do this by using addition. Start with the following equations:
2x - y =20
2x + y =12
Now add going down the rows which equals:
4x = 32
The y's cancel out because y - y = 0, now divide both
sidesby 4
x = 8
Now we will use substituion to solve for y
Let's do this by using the smaller equation.
2x + y = 12
We know that x = 8, so substitute 8 for x
2(8) + y = 12
16 + y = 12
Subtract 16 from both sides to get y by itself
y = -4
You can check the answers for x and y by substituting the answers back into the original equations to make sure they equal out.
2x + y = 12
2(8) + (-4) = 12
16 - 4 = 12
12 = 12
2x - y + 20
2(8) - (-4) = 20
16 + 4 = 20
20 = 20
So your solution is (8,-4)
|
|
|
