SOLUTION: Hello, Im seeking help regarding Graphing,Subsitution,And Elimination Next to each equation I have a problem number in Parenthesis. This shouldnt affect you at all, But its there f

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Hello, Im seeking help regarding Graphing,Subsitution,And Elimination Next to each equation I have a problem number in Parenthesis. This shouldnt affect you at all, But its there f      Log On


   

Question 17873: Hello, Im seeking help regarding Graphing,Subsitution,And Elimination Next to each equation I have a problem number in Parenthesis. This shouldnt affect you at all, But its there for reference on my part. Thank you in advance to whoevern decides to aid me.
My first problem (5) is x=4y+5
x=3y-2
How do I get a variable here? I have to do this problem using subsitution. The two x's confuse me. I've never seen a problem like this and its the only one I have. Some help please!! :)
My next problem(7) is with elmination
3x-5y=16
-3x+2y=-10

How do I do this? I've tried several times and just cant solve it.
My next problem is also similiar to the one before last, I can not get a variable to cancel out, But I have to multiply it and thus dont know what to multiply by!!!!!!!!

4x+7y=6
6x+5y=20
I have to decide what to do this one by Either sub,graphing,or elim
(16)
x+2y=6
3x-2y=2
-Sincerely Jordan.
Answer by Alwayscheerful(414) About Me  (Show Source):
You can put this solution on YOUR website!
Wow, long question!
This question seems a little old, but I'll still answer it.
Your question 5 with substitution
x=4y%2B5
x=3y-2
Don't let the 2 x's confuse you.
All you need to do (because you are using substitution) is move one of the x's over and the number without a variable over to take its spot.
4y-x=-5 - New equation
Take the second equation and substitute!
4y-%283y-2%29=-5
4y-3y%2B2=-5
y=-7
Plug -7 back into the original equation to get X
x=4%28-7%29%2B5
x=-28%2B5
x=-23
*CHECK*
Plug (-23,-7) back into your answer to make sure you get the right answer. On homework, I would just check the answer in the book to make sure you got it right, but on tests, I highly reccomend checking.
-23=4%28-7%29%2B5
-23=-23 CORRECT!
Your question 7 with elimination
3x-5y=16
-3x%2B2y=-10
Great! You already have coinciding X terms! All you need to do is get rid of it. How? Add 3 to -3 and you get 0!
-3y=6
y=-2
Plug -2 back in the original equation to find X
3x-5%28-2%29=16
3x%2B10=16
3x=6
x=2
*CHECK*
3%282%29-5%28-2%29=16
6%2B10=16 CORRECT!
Your 3rd question using elimination
4x%2B7y=6
6x%2B5y=20
All you have to do is multiply the X or Y values to make them equal.
For X, you can make them both 24 by multiplying the top by 6 and the bottom by 4
For Y, you can make them both 35 by multiplying the top by 5 and the bottom by 7
I'll make the X values 24 because the number is smaller.
24x%2B42y=36
24x%2B20y=80
Subtract
22y=-44
y=-2
Plug -2 for Y to get X
4x%2B7%28-2%29=6
4x-14=6
4x=20
x=5
*CHECK*
4%285%29%2B7%28-2%29=6
20-14=6 CORRECT!
Your question 16 (I reccomend elimination)
x%2B2y=6
3x-2y=2
Add
4x=8
x=2
Plug 2 in for X to get Y
%282%29%2B2y=6
2y=4
y=2
*CHECK*
%282%29%2B2%282%29=6
2%2B4=6 CORRECT!
Hope this all helps!