i need 2x - 4 = 8?

When you are beginning to learn algebra, there are a few major concepts you need to base your understanding on...

1. What an equal sign actually means. Unfortunately, most people don't understand what an equal sign means...it is NOT a sign for "the answer is". An equal sign merely means that you have the same amount of 'stuff' on one side as you do the other. Take an easy equation, 2+2=4....2+2 is the same amount as 4. Now take equations...again, another simple one...2+x=5. For you to have the same amount of stuff on both sides, x would have to be 3. 2+3=5, so If you did this correctly, 5=5 (which would be true so it's right!)

2. Your ultimate goal is to get your variable (x or y or whatever) to be all by itself.

3. The way you get rid of numbers so your variable can be by itself, is by doing the opposite of the number. So if it's -2, you have to add 2 (because that would give you 0)....if it's 3x (which is 3 times x), it would be divided by 3. 3x/3= if you reduced 3/3, it would be 1...so 3x/3 is reduced to 1x (which is the same as x)

4. Because you're using an equal sign (again meaning same amount on both sides), what you do to one side, you have to do to the other...So if you take 2 away from one side, you have to take 2 away from the other side to keep that 'equalness' or balance.

So back to your original question...

You have 2x-4=8. Since our goal is to get x on side and numbers on the other, let's get rid of the negative 4 first. To do so, you'd have to add 4 (which would give you zero). What you do to one side, you have to do to the other, so you'd have to add 4 to 8 also.

2x-4+4=8+4
2x=12

Now to get rid of the 2 from 2x (or 2 times x) you have to do the opposite, which is divide by x (2/2x gives you 1x which is the same as x). Of course, do the same thing to the other side...

2x/2=12/2
x=6

Too see if you equation is correct, simply plug in 6 for the x.

2(6)-4=8
12-4=8
8=8...which is true so your solution is right!

2x - 4 = 8
2x = 8 + 4
2x = 12
x = 12/2
x = 6

2x - 4 = 8
2x = 8 + 4
2x = 12
x = 12/2
x = 6

6

note
2x - 4 = 8
add 4 to both sides
2x = 12
and divide by 2
x = 6

2x - 4 = 8
2x = 8 + 4
2x = 12
x = 6

6

2x = 12
x = 6

6

2x-4=8
+4 +4
2x=12
/2 /2
x=6