(-\frac{5}{12}+2\frac{4}{15})*(-45)=
źródło:
=(-\frac{25}{60}+2\frac{16}{60})*(-45)=
=(-\frac{25}{60}+\frac{136}{60}*(-45)=
=\frac{111}{60}*(-45)=-\frac{333}{4}=-83\frac{1}{4}