so I have a hard time understanding linear equations for math...

coolgirlspyer90

coolgirlspyer90

Active Member
Joined
Jun 11, 2008
Messages
1,672
Reaction score
0
so, I have exams coming up pretty soon, and the most difficult topic I'm having a hard time in algebra is linear equations. I just don't get it at all. my interpreter tried to help me with it, but nope, nothing. so I thought I turn to here for some more help. and a good review before exams too. an explaination or some examples might help!!
 
The idea is to get the variable on one side of the equal sign and the numbers on the other.

For example

4x-12=2x+14 solve for x and graph.
+12 +12 I started from the left hand side using 12. Because it is -12, I add 12 to make it 0 and therefore gets rid of the 12 on the left hand side. I did the same to the 14 on the right hand side to get 26.
4x =2x+26 That leaves me with this.
4x-2x 2x-2x Then from the right hand side I subtracted the 2x from itself to get rid of it then I also subtracted the 2x from the 4x which leaves me with 2x on the left hand side that gets me to this:
2x=26
2x/2 = 26/2 I then divided by the number two that is multiplied with the x on both sides, that gets me to the final answer of:
x = 13

The key to linear equations is knowing the order of operations and knowing when to do what and when.
 
Dixie said:
The idea is to get the variable on one side of the equal sign and the numbers on the other.

For example

4x-12=2x+14 solve for x and graph.
+12 +12 I started from the left hand side using 12. Because it is -12, I add 12 to make it 0 and therefore gets rid of the 12 on the left hand side. I did the same to the 14 on the right hand side to get 26.
4x =2x+26 That leaves me with this.
4x-2x 2x-2x Then from the right hand side I subtracted the 2x from itself to get rid of it then I also subtracted the 2x from the 4x which leaves me with 2x on the left hand side that gets me to this:
2x=26
2x/2 = 26/2 I then divided by the number two that is multiplied with the x on both sides, that gets me to the final answer of:
x = 13

The key to linear equations is knowing the order of operations and knowing when to do what and when.
Click to expand...
I'd put spaces in between steps, but that is pretty clear and simple example. Maybe more complex linear equations are being used in her class though.
 
tigersharkdude said:
Could you post the equations that you are currently doing in your math class?
Click to expand...



1/2Y=1

5x+6y=3x+2

2+ 1/2x=y



We also studied linear equations by using a graph chart and tables. The graphing part is kind of hard for me as well My teacher said that if it has a 2nd power to whatever or a variable thats along in the equation it is not an linear equation. Is that true?
 
The first thing you need to do in linear equations is isolate the variable. Meaning that you need to get the numbers on one side, and the variable (X, Y, etc) on the other

1) For the first problem the variable "y" is a fraction. They way to get rid of this fraction is by multiplying both sides by the denominator (bottom number)
Equation:1/2Y=1

Step one-Multiply both sides by the denominator "2"
2 x 1/2Y= 1 x 2
2x1/2=1 1x2=2
Answer: Y=2

2)On this equation you have an X variable and a Y. Your goal is to find X&Y
Equation: 5x+6y=3x+2
Find X
To find X you must isolate it, meaning have X on one side and Y and number on the other.
5x+6y=3x+2

Step one-Move X to left side
5x+(-3x)+6y=3x+(-3x)+2
2x+6y=2

Step two-Move the Y variable to the right side
2+6y+(-6y)=2+(-6y)
2x=2-6y

Step three-You must now isolate X by dividing by the variable's leading number "3"
(2x/2)=(2/2)+(-6y/2)
Answer: x=-3y

Find Y
5x+6y=3x+2

Step one-Move Y to left side
5x+6y+(-5x)=3x+2+(-5x)
6y=2+(-2x)

Step two-You must now isolate Y by dividing by the variable's leading number "6"
(6y/6)=(2/6)+(-2x/6)
y=(2/6)+(-2/6)x

Step three-Reduce the fractions
Answer: Y=1/3-1/3x

3) On this equation you have an X variable and a Y. Your goal is to find X&Y

Find X: To find X you must isolate it, meaning have X on one side and Y and number on the other.

2+ 1/2x=y

Step one: Move the 2 from the left to the right

2+(-2)+1/2x=y+(-2)
1/2x=y-2

Step two: Multiply both sides of the equation by the Denominator "2"
2 x (1/2x)= (2 x y) - (2 x -2)
x=2y-(-4)
Answer: x=2y+4

Find Y
2+ 1/2x=y

Step One: Y is already by itself and has no leading number. Therefore

Answer: Y=1/2x + 2



If you have any math questions, feel free to PM me. I have a math book I can send you, BUT its college Algebra.
 
Last edited:
tigersharkdude said:
The first thing you need to do in linear equations is isolate the variable. Meaning that you need to get the numbers on one side, and the variable (X, Y, etc) on the other

1) For the first problem the variable "y" is a fraction. They way to get rid of this fraction is by multiplying both sides by the denominator (bottom number)
Equation:1/2Y=1

Step one-Multiply both sides by the denominator "2"
2 x 1/2Y= 1 x 2
2x1/2=1 1x2=2
Answer: Y=2

2)On this equation you have an X variable and a Y. Your goal is to find X&Y
Equation: 5x+6y=3x+2
Find X
To find X you must isolate it, meaning have X on one side and Y and number on the other.
5x+6y=3x+2

Step one-Move X to left side
5x+(-3x)+6y=3x+(-3x)+2
3x+6y=2

Step two-Move the Y variable to the right side
3x+6y+(-6y)=2+(-6y)
3x=2-6y

Step three-You must now isolate X by dividing by the variable's leading number "3"
(3x/3)=(2/3)+(-6y/3)
Answer: x=2/3-2y

Find Y
5x+6y=3x+2

Step one-Move Y to left side
5x+6y+(-5x)=3x+2+(-5x)
6y=2+(-2x)

Step two-You must now isolate Y by dividing by the variable's leading number "6"
(6y/6)=(2/6)+(-2x/6)
y=(2/6)+(-2/6)x

Step three-Reduce the fractions
Answer: Y=1/3-1/3x

3) On this equation you have an X variable and a Y. Your goal is to find X&Y

Find X: To find X you must isolate it, meaning have X on one side and Y and number on the other.

2+ 1/2x=y

Step one: Move the 2 from the left to the right

2+(-2)+1/2x=y+(-2)
1/2x=y-2

Step two: Multiply both sides of the equation by the Denominator "2"
2 x (1/2x)= (2 x y) - (2 x -2)
x=2y-(-4)
Answer: x=2y+4

Find Y
2+ 1/2x=y

Step One: Y is already by itself and has no leading number. Therefore

Answer: Y=1/2x + 2



If you have any math questions, feel free to PM me
Click to expand...



Thanks!!
 
I'm more confused than when I first started the thread. :dizzy:

Now I remember why I don't teach Algebra. :P
 
I get to teach it next year to my son for home school. I am not looking forward to it, but I am studying it now to get ready.
 
Just remember if ya'll need any help PM me. Im pretty good at math. When I was taking my college algebra class I corrected the teacher A LOT
 
coolgirlspyer90 said:
1/2Y=1

5x+6y=3x+2

2+ 1/2x=y



We also studied linear equations by using a graph chart and tables. The graphing part is kind of hard for me as well My teacher said that if it has a 2nd power to whatever or a variable thats along in the equation it is not an linear equation. Is that true?
Click to expand...

For graphing you first want to isolate Y using the methods that tigersharkdude described. After that, pick 2 values for X and for each one, solve the equation to get the corresponding value of Y. Any 2 values of X will work, so you can pick numbers like 0 or 1 that make the math easy. Then plot those 2 points on the graph and draw the line between them. This works because for any 2 points, there is only 1 way to draw a line that connects them.

The 2nd power thing is true; that makes it a quadratic equation which is a curve, not a line. It doesn't sound like you have to worry about drawing them though (for reference you would need 3 points to do so)
 
Back
Top