SOLUTION: Can someone help me with this .also i need clarification when doing Elimination. how do i know when to add and subtract can i have 2 examples of showing when to add also and can s

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Question 593805: Can someone help me with this .also i need clarification when doing Elimination. how do i know when to add and subtract can i have 2 examples of showing when to add also and can someone help me with these 2 equations.I am trying to practice for exams.
4(2x-y=-2
2(4x+y=24

8x-12y=-2
- 8x+2y=48
- __________
- -10y +-50
- Y=-50/-10
- Y-5
4x+y=24
4x+5=24
4x=24-5
4x=19
.....this isn’t looking right so far
Also
Y=x+3
Y=x^2
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Can someone help me with this .also i need clarification when doing Elimination. how do i know when to add and subtract can i have 2 examples of showing when to add also and can someone help me with these 2 equations.I am trying to practice for exams.
4(2x-y=-2
2(4x+y=24
8x-12y=-2 *** Is this a different problem? Where did you get -12y ?
===========
4(2x-y=-2
2(4x+y=24
---
2x-y=-2
4x+y=24
-------------- Add
6x = 22
x = 11/3
------
2x-y=-2
y = 2x + 2
y = 28/3
-----------
=============
- 8x+2y=48
- __________
- -10y +-50
- Y=-50/-10
- Y-5
4x+y=24
4x+5=24
4x=24-5
4x=19
.....this isn’t looking right so far
Also
Y=x+3
Y=x^2
-----
Both equal y, so
x + 3 = x^2
x%5E2+-+x+-+3+=+0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-1x%2B-3+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-1%29%5E2-4%2A1%2A-3=13.

Discriminant d=13 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--1%2B-sqrt%28+13+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-1%29%2Bsqrt%28+13+%29%29%2F2%5C1+=+2.30277563773199
x%5B2%5D+=+%28-%28-1%29-sqrt%28+13+%29%29%2F2%5C1+=+-1.30277563773199

Quadratic expression 1x%5E2%2B-1x%2B-3 can be factored:
1x%5E2%2B-1x%2B-3+=+%28x-2.30277563773199%29%2A%28x--1.30277563773199%29
Again, the answer is: 2.30277563773199, -1.30277563773199. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-1%2Ax%2B-3+%29

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y = x + 3