Subtract 4m 75cm from 10m 50cm. For each of the following fractions, list other fractions which are equal: a) 4/7

$1 \text{m} = 100 \text{ cm}$.
The $10 \text{m}$ becomes $9 \text{m}$, and $50 \text{ cm}$ becomes $50 \text{ cm} + 100 \text{ cm} = 150 \text{ cm}$.

$$\begin{array}{c} 9 \text{m } 150 \text{cm} \\ - \quad 4 \text{m } 75 \text{cm} \\ \hline \end{array}$$

$150 \text{ cm} - 75 \text{ cm} = 75 \text{ cm}$
$9 \text{m} - 4 \text{m} = 5 \text{m}$

$$\begin{array}{c} 9 \text{m } 150 \text{cm} \\ - \quad 4 \text{m } 75 \text{cm} \\ \hline 5 \text{m } 75 \text{cm} \end{array}$$

The result is $\boxed{\text{5m 75cm}}$.

$$\frac{4 \times 3}{7 \times 3} = \frac{12}{21}$$

Two equivalent fractions are $\boxed{\frac{8}{14}, \frac{12}{21}}$.

$$\frac{1 \times 3}{11 \times 3} = \frac{3}{33}$$

Two equivalent fractions are $\boxed{\frac{2}{22}, \frac{3}{33}}$.

$$\frac{2 \times 3}{9 \times 3} = \frac{6}{27}$$

Two equivalent fractions are $\boxed{\frac{4}{18}, \frac{6}{27}}$.