Rearranging Formulas Quiz

1. Make $x$ the subject of $y = 2x - 5$

• A. $x = \frac{y+5}{2}$
• B. $x = \frac{y-5}{2}$
• C. $x = 2y+5$
• D. $x = \frac{y}{2}-5$

2. Make $h$ the subject of $V = \pi r^2 h$

• A. $h = \frac{V}{\pi r^2}$
• B. $h = V\pi r^2$
• C. $h = \pi r^2 V$
• D. $h = \frac{\pi r^2}{V}$

3. Make $x$ the subject of $y = \sqrt{x-2}$

• A. $x = y^2 - 2$
• B. $x = y^2 + 2$
• C. $x = \sqrt{y}+2$
• D. $x = y-4$

4. Make $x$ the subject of $ax + 3 = bx + 7$

• A. $x = \frac{4}{a-b}$
• B. $x = \frac{4}{a+b}$
• C. $x = \frac{a-b}{4}$
• D. $x = 4(a-b)$

5. A student rearranges $y = \sqrt{x}+3$ and writes $x = y^2 - 9$. What error have they made?

• A. No error, this is correct
• B. They should not have subtracted 3 first
• C. They squared before isolating the root, incorrectly expanding $(y-3)^2$ as $y^2-9$
• D. They forgot to divide