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Rearranging equations

We can express an equation in terms of the other variable.

For example, P = 16 - 2Q

To rearrange the equation so that it is written as Q= take each term and move to the other side of the equal sign using the opposite operation until you only have Q remaining on the left.

e.g. Rearrange P = 16 - 2Q to make Q the subject of the equation

P = 16 - 2Q

P+ 2Q = 16     Take -2Q to the other side of the equal sign by adding 2Q to both sides

2Q = 16 - P     Take P to the other side of the equal sign by subtracting P to both sides

Q = \frac{16-P}{2}           Divide both sides by 2

Now if we have a value for P we can find Q

e.g. Find Q when P=6

Q = \frac{16-6}{2}

Q= 5

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