Question

1 1/9+2,75+1/3;
3,5+5 1/7-2 3/14;
8,5+5/6-6,25;
7,6-2/3+2 1/15; 
2,25+11 1/15-7 1/6;
6,8-2 1/3+1,2

Answer 1

1
$1 frac{1}{9}+2,75+ frac{1}{3}= 1+2+frac{1}{9}+0,75+ frac{1}{3}=3+ frac{1}{9}+ frac{3}{4}+ frac{1}{3}=\ = 3+ frac{4cdot1+9cdot3+3cdot4cdot1}{36}=3+ frac{4+27+12}{36}=3+ frac{43}{36}=3+1 frac{7}{36}=4 frac{7}{36};$
2.
$3,5+5frac{1}{7}-2 frac{3}{14}=3+5-2+ frac{1}{2}+ frac{1}{7}- frac{3}{2cdot7}=\ =6+ frac{7cdot1+2cdot1-3}{14}=6+ frac{6}{14}=6 frac{1}{7} ;$
3.
$8,5+ frac{5}{6}-6,25=8-6+ frac{1}{2}+ frac{5}{6}- frac{1}{4}=2+ frac{6+10-3}{12}=2+ frac{13}{12}=\ =2+1 frac{1}{13} =3 frac{1}{3};$
4.
$7,6- frac{2}{3}+2 frac{1}{15}=7+2+ frac{3}{5}- frac{2}{3}+ frac{1}{15}=9+ frac{9-10+1}{15}=9;$
5.
$2,25+11 frac{1}{15}-7 frac{1}{6}=2+11-7+ frac{3}{4}+ frac{1}{15}- frac{1}{6}=\ =6+ frac{45+4-10}{60}=6+ frac{39}{60}=6 frac{13}{20}$

6.
$6,8-2 frac{1}{3}+1,2=6-2+1+ frac{4}{5}- frac{1}{3}+ frac{1}{5} =6-2+1+1+ frac{1}{3}=6 frac{1}{3};$