Question

помогите пожалуйста ​

Answer 1

д) $\frac{5}{12} +(-\frac{7}{9} )= \frac{15-28}{36} =\frac{-13}{36} =-\frac{13}{36}$

е) $-\frac{11}{42} +\frac{5}{28}=\frac{-22+15}{84}=\frac{-7}{84} = -\frac{7}{84} =-\frac{1}{12}$

ж) $-\frac{5}{7} +1=\frac{-5+7}{7} =\frac{2}{7}$

з) $2\frac{9}{20} +(-2\frac{4}{15} )=\frac{89}{40}-2\frac{4}{15} =\frac{89}{40} -\frac{34}{15} =\frac{267}{120} -\frac{272}{120} =\frac{-5}{120} =-\frac{1}{24}$