Question

Va rog ajutatima sa calculez :
6  2\7 - 4  1\7 =?
8  4\5 - 3   1\5=?
12  1\9 - 5   4\9=?
18   2\11 - 7   5\11=?

Answer 1

$6 \frac{2}{7} - 4 \frac{1}{7} =$

$= \frac{6*7+2}{7} - \frac{4*7+1}{7} =$

$= \frac{44}{7} - \frac{29}{7} =$

$= \frac{15}{7} =$

$= 2 \frac{1}{7}$

sau:

$6 \frac{2}{7} - 4 \frac{1}{7} =$

$=6 + \frac{2}{7} - (4 + \frac{1}{7} )=$

$=6 + \frac{2}{7} - 4 - \frac{1}{7} =$

$=2+ \frac{1}{7} =$$2 \frac{1}{7}$


$8 \frac{4}{5} - 3 \frac{1}{5} =$

$= \frac{44}{5} - \frac{16}{5} =$

$= \frac{28}{5} =$

$=5 \frac{3}{5}$

sau:

$8 \frac{4}{5} - 3 \frac{1}{5} =$

$=8+ \frac{4}{5} - (3+ \frac{1}{5} )=$

$=8+ \frac{4}{5} - 3- \frac{1}{5} =$

$=5+ \frac{3}{5} =$$5 \frac{3}{5}$


$12 \frac{1}{9} - 5 \frac{4}{9} =$

$= \frac{109}{9} - \frac{49}{9} =$

$= \frac{60}{9} =$

$= 6 \frac{6}{9} = 6 \frac{2}{3}$

sau:


$12 \frac{1}{9} - 5 \frac{4}{9} =$

$=12+ \frac{1}{9} - (5+ \frac{4}{9} )=$

$=12+ \frac{1}{9} - 5- \frac{4}{9} =$

$=11+(1+ \frac{1}{9} ) - 5- \frac{4}{9} =$

$=6+ \frac{10}{9} - \frac{4}{9} =$

$= 6+ \frac{6}{9} = 6 \frac{6}{9} = 6 \frac{2}{3}$


$18 \frac{2}{11} - 7 \frac{5}{11} =$

$= \frac{200}{11} - \frac{82}{11} =$

$= \frac{118}{11} =$

$= 10 \frac{8}{11}$