Hola no se realizar los ejercicios de matemáticas siguientes

c)

$$\begin{align}&\frac{(-3-2)(7-9)}{\left(\frac 12 -\frac 54  \right)\div \frac 12} =\\ &\\ &\\ &\\ &\frac{(-5)(-2)}{\left(\frac{2-5}{4}  \right)\div \frac 12}=\\ &\\ &\\ &\frac{10}{-\frac 34 \div \frac 12} =\\ &\\ &\\ &\frac{10}{-\frac{3·2}{4·1}}= -\frac{10}{\frac 64}=-\frac{10·4}{6}=-\frac{40}{6}=-\frac{20}{3}\end{align}$$

d)

$$\begin{align}&\frac{\frac{3}{10}\div \frac 95 \div \frac 12}{\frac 13 \div \frac{1}{12}+\left( \frac 13 - \frac{12}{3} \right)}=\\ &\\ &\\ &\frac{\frac{3·5}{10·9} \div \frac 12}{\frac{1·12}{3·1}+\left(-\frac{11}{3}  \right)} =\frac{\frac{15}{90}\div \frac 12}{\frac{12}{3}-\frac{11}{3}} =\\ &\\ &\\ &\\ &\frac{\frac{15·2}{90·1}}{\frac 13}= \frac{\frac{30}{90}}{\frac 13}= \frac{30·3}{90·1}=\frac {90}{90}= 1\end{align}$$

Y eso es todo.