Question

ayuda porfavor es un examen ​

Answer 1

Respuesta:

=-2

Explicación paso a paso:

$\left(\frac{1}{5}+\frac{1}{4}\right)\div \frac{9}{20}-\left(3-\frac{3}{5}\right)\cdot \frac{15}{12}$

$=\left(\frac{1}{5}+\frac{1}{4}\right)\div \frac{9}{20}-\left(3-\frac{3}{5}\right)\frac{5}{4}$

$=\frac{9}{20}\div \frac{9}{20}-\left(3-\frac{3}{5}\right)\frac{5}{4}$

$=\frac{9}{20}\div \frac{9}{20}-\frac{12}{5}\cdot \frac{5}{4}$

$=1-\frac{12}{5}\cdot \frac{5}{4}$

$=1-3$

$=-2$

Espero te sierva,  te agradecería si me das corona

:)