how to do a one-step equation for algerbra

Question

.i need to know how to complete algerbra equations  with only one variable

Answer 1

To break down Tom's (rather excellent) response a little further, and to demonstrate the mechanics of his example:

 

An equal sign is kind of like the word "is"; it means that the two things on either side are two different ways of saying the same thing.  For example, both 4-3 and 1 are two different ways of expressing the same number, so we can write

 

4-3=1

 

This also means that we cannot change one side of an equation without also changing the other side the same way and still have a true equation.  Thus, we cannot have

 

4-3=1+3

 

That's not a true equation.  However, if we do the same thing to both sides of the equation, the equation will stay true.  Thus,

 

4-3+3=1+3

 

is a true equation.  This is useful in algebra because it allows us to, as Tom says, "get all terms in x on on side of the equation and all constant values on the other".  The key there is to do the _opposite_ operation from the one you're trying to move.  That way, on one side, the two operations will cancel each other out.  Thus, if you want to move a number that has been added, you subtract it from both sides, and vice versa.  If you want to move a number that has been multiplied, you divide it from both sides, and vice versa. So, when we have an equation like

 

3x+8=35

 

we can subtract eight from both sides.  That way, we no longer have a term that doesn't involve x on the right, but the equation remains true.  Here, let me show you:

 

3x+8-8=35-8

3x=27

 

Do you see how that works?  We can then do something similar by dividing both sides by three.  Since x is multiplied by three on the right side, that reduces to simply x (which is our goal in this whole process) and since we're doing to it to both sides, the equation will remain true.

 

3x/3=27/3

x=9

 

And now we have a value for x, which we can check by plugging it into the original equation and seeing if it remains true:

 

3*9+8=35

27+8=35

35=35

 

It does!  Here's Tom's other example with these mechanics added in:

 

5x-7=3x+21

5x-7+7=3x+21+7

5x=3x+28

5x-3x=3x+28-3x

2x=28

2x/2=28/2

x=14

Answer 2

An example of a equation with one variable would be something like the following

 

3x + 8 = 35

 

to solve for x you must get all terms in x on on side of the equation and all constant values on the other and then perform the calculation need to find x

 

3x = 35 - 8

3x = 27

x = 9

 

Another example

 

5x - 7 = 3x + 21

5x - 3x = 21 + 7

2x = 28

x = 14 

 

hope this helps