The subject of a formula is the variable that is being worked out. It can be recognised as the letter on its own on one side of the equals sign. For example, in the formula for the area of a rectangle ...

Calculating the interest rate using the present value formula can at first seem impossible. However, with a little math and some common sense, anyone can quickly calculate an investment's interest ...

Rearranging the formula for the circumference of a circle makes the radius the subject. Start with the new subject and write out the function machine for the formula, showing each operation step by ...