# Changing The Subject - Odd One Out

## Which of the five versions of the formula is the odd one out because it is not equivalent to the other four?

##### Level 1Level 2Level 3Level 4Level 5Level 6DescriptionHelpMore Algebra

This is level 5; Formulas including squares or square roots. You can earn a trophy if you answer the questions correctly.

 A$$b=\sqrt a$$ B$$b = \frac ab$$ C$$\frac{a}{b^2}=1$$ D$$b=2a$$ E$$a=b^2$$
 A$$\frac{A}{\pi}=r^2$$ B$$A=\pi r^2$$ C$$r=\sqrt{\frac{A}{\pi}}$$ D$$\pi = \frac{A}{r^2}$$ E$$A=\sqrt{\frac{r^2}{\pi}}$$
 A$$h=\frac{V}{\pi r^2}$$ B$$r=\sqrt{\frac{V}{\pi h}}$$ C$$V=\pi r^2 h$$ D$$r^2=\frac{V}{h \pi}$$ E$$r=\frac{V}{\pi h}$$
 A$$a^2=b^2+c^2$$ B$$a^2=b^2-c^2$$ C$$b^2=a^2-c^2$$ D$$c^2=a^2-b^2$$ E$$a=\sqrt{b^2-c^2}$$
 A$$\pi = \frac{4V}{3r^3}$$ B$$V=\frac43 \pi r^3$$ C$$\pi = \frac{3V}{4r^3}$$ D$$r^3=\frac{3V}{4 \pi}$$ E$$3V=4 \pi r^3$$
 A$$b=\frac{a^2}{c}$$ B$$c=\frac{a^2}{b}$$ C$$b=\frac{a}{c^2}$$ D$$a=\sqrt{bc}$$ E$$a^2 = bc$$
 A$$d^2=2a+1$$ B$$d=\sqrt{2a+1}$$ C$$2a=d^2-1$$ D$$a=\frac{1-d^2}{2}$$ E$$a=\frac{d^2-1}{2}$$
 A$$p=\frac{f}{q^2}$$ B$$\frac pq = f^2$$ C$$f=\sqrt{\frac pq}$$ D$$p=f^2 q$$ E$$\frac qp = \frac{1}{f^2}$$

This is Changing The Subject - Odd One Out level 5. You can also try:
Level 1 Level 2 Level 3 Level 4 Level 6

## Instructions

Try your best to answer the questions above. Choose one of the five possible answers. When you have finished click the "check" button. If you have any questions wrong, do your best to do corrections but if there is anything you don't understand, please ask your teacher for help.

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#### Striped Sweets

Colour the sweet wrappers so that no two are the same. A multi-level activity designed to encourage a systematic strategy for finding all of the different permutations.

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## Go Maths

Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. Click here for more activities designed for students in upper Secondary/High school.

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## Description of Levels

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Level 1 - Formulas which can be rearranged by adding or subtracting terms from both sides

Example: Make e the subject of the formula d = e - f

Level 2 - Formulas which can be rearranged by multiplying or dividing both sides by a value

Example: Rearrange the formula n = mp

Level 3 - Formulas which can be rearranged by adding, subtracting, multiplying or dividing both sides by a value

Example: Rearrange the formula b = a + cd

Level 4 - Formulas including brackets or expressions in the numerator or denominator of a fraction

Example: Rearrange the formula p = s(t + 2)

Level 5 - Formulas including squares or square roots

Example: Rearrange the formula d² = 2a + 1

Level 6 - Finding the unknown which is not the subject of a formula

Example: If m = n² + 2p, find p when m=8 and n=10

## Help

In level 6, there are two solutions to the questions which involve finding a square root (which could be positive or negative). This program will accept either of the possible answers.

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