Welcome to the forum.
The rules for algebra are just the same rules that are used for arithmetic. If ever you are uncertain about some algebra just try a similar thing with numbers. Here's a couple of examples to show what I mean:
If I multiply just one term on the left and one on the right by 4, I'll get
As you can see this is NOT correct.
You must multiply every thing by 4
Now we have a correct result.
Let's compare that with an addition. I'll start with the same equation and add 5/4 to each side.
Both sides are now 9/4 so it is correct to do it this way.
The two rules that are being used here are:
(1) If we have a correct equation it will still be correct if we multiply every term on each side by a number.
(2) If we have a correct equation it will still be correct if we add the same amount to each side.
Hope that helps.
Bob
]]>Say I have the equation 4x+(3/4)-1=5+20
If I want to get rid of the fraction (3/4) I have to multiply 4 by the entire equation on both sides:
4(4x+(3/4)-1)=(5+20)4
The same goes for division. But.. when adding or subtracting, instead of it being, say when adding 1 to both sides:
4x+(3/4+1)-(1+1)=(5+1)+(20+1) it's simply 4x+(3/4)-1+1=5+20+1
Why is that?
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