Question

Вычислите
а) -4,1+1,8
б) -1 5/6+(-3 5/12)
в) -1 2/12+3 5/6+(-1,7)​

Answer 1

$1)-4,1+1,8=-(4,1-1,8)=-2,3\\2)-1\frac{5}{6}+(-3\frac{5}{12})=-1\frac{5}{6}-3\frac{5}{12}=-(1\frac{5}{6}+3\frac{5}{12})=-((1+3)+(\frac{5}{6}+\frac{5}{12}))=-(4+\frac{5}{4})=-(4+1\frac{1}{4})=-(4+1+\frac{1}{4})=-(5+\frac{1}{4})=-5\frac{1}{4}=-\frac{21}{4}=-5,25\\3)-1\frac{2}{12}+3\frac{5}{6}+(-1,7)=-\frac{14}{12}+\frac{23}{6}-1,7=-\frac{14}{12}+\frac{23}{6}-\frac{17}{10}=\frac{29}{30}$