# Rearranging Formulae

## Language of Formulae

### The diagram below shows the basic parts of a formula:- ## Method 1 - The "Triangle Method"

### The diagram below shows the basic layout of the triangle method:- ### In order to change the subject of the formula to a different letter, simply "cover over" the required subject, and whatever is left gives the rearranged formula. ## Example 1 -

### The circuit below shows a bulb within a series circuit. ### Use Ohm's Law (V = I x R) to find the Resistance of the bulb. ## Method 2 - "Crossing the Equals Sign" Method

### The next simple method is known as the "crossing the equals sign" method. In this method, the formula is changed by moving parts from one side of the equals sign to the other one at a time, and reversing the sign:- ## Example 2 -

### The Acceleration of an object is given by the formula below:- ### Step 1 : Move the "divide by t " across the equals sign and change to "multiply by t":- ### Step 2: Move the "subtract by u" across the equals sign and change to "add by u":- ### Step 3 : Rewrite with the subject on the left:- ## Method 3 - "Same thing to each side" Method

### Therefore in order to "move" a part from one side of the Equals sign to the other, the following steps are actually performed:- ### Step 1 : Multiply each side by " t ":- ### Step 2 : Simplify any sections of "divide by itself = 1":- ### Step 3 : Simplify any sections of "multiplied by 1 = itself":- ### Step 4 : Add "u" to each side :- ### Step 5 : Simplify any sections of " value subtracted by itself = 0":- ### Step 6 : Rewrite with the subject on the left:- 