# Changing the Subject of a Formula

A document which will teach you how to change the subject of a formula.

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• Created by: Lol
• Created on: 16-01-11 20:26
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## Pages in this set

### Page 2

Example 1
Make "X" the subject of this formula ­

X+Y = Z

When we are making something the subject of the formula, it means we
want to have the term on its own. We need to take every term away from
what we want the subject to be. In…

### Page 3

Example 2
Make "X" the subject of this formula ­

2X = Y

Again in this example, we want to get every other term away from "X". In
this particular example, we can divide each side by 2 to get "X" on its own.

2X = Y [/2]

X =…

### Page 4

Example 3
Make "X" the subject of this formula ­

X = Y

This is when things begin to get a little tricky. We need to get rid of the
square root on the "X" to make it the subject. We can do this by squaring
both sides.

X =…

### Page 5

Example 4
Make "X" the subject of this formula ­

3(X+Y) = Z

We will now progress into problems which require 2 stages. The first thing
we should do is get rid of the bracket. We can do this by dividing each side
by 3. Finally, to get "X" by…

### Page 6

Example 5
Make "X" the subject of this formula ­

Y/X²-1 = 2

Let's recap what we have learned so far. Remember, you want to get "X"
by itself.

Y/X²-1 = 2 [MULTIPLY X² - 1]

Y = 2(X²-1) [BRACKETS]

Y = 2X² - 2 [+2]

Y+2 = 2X² [/2]…

### Page 7

Example 6
Make "X" the subject of this formula ­

XN+TB = XV

Now this formula look a little different ­ there's two "X's". In order to get this
down to just one "X", we must get both "X's" to the same side, and then
factorise them together. It will…