ALGEBRA -Why does a term in an equation change sign when it is taken to the other side ?

It doesn't really change. It's just like adding at one side and subtracting the same from the other side just to maintain the existing balance

say for example, express x in terms of y (subject of formula)

5x = y + 3

if you're moving the 5 to the other side, you are dividing both sides by 5.

5x / 5 = (y+3) / 5

x = (y+3) / 5

and to express y in terms of x

you need to move the three, which means:

y+3 - 3 = 5x - 3

(subtract 3 from both sides to maintain equality)

y = 5x - 3

basically, if you're moving an +or- value over, you're actually subtracting/adding the value away from both sides. and if it's a *or/ value, you divide / multiply the value away.

In algebra

ex

4=2+2

dont think like we are shifting one thing from one side

you can see like this

this the one way

4=2+2

4-2=2

also

4-2 = 2+2+-2

we are subtrating two from both sides

4-2 = 2

so if you are taking some thing from one side you have to subtract that from the other side also

Consider some Eq. a+b+c=x+y

Now suppose we want to carry b on the RHS.so subtact b on both sides.We get

a+b+c-b=x+y-b

implies a+c=x+y-b

since we donot go step by step so this is equivalent to saying that a term changes sign when it changes the side.

Ivan

To get marks from the teacher.....(actually speaking)

To preserve equality