$a)4\frac{2}{5}+0,15=4\frac{4}{10}+0,15=4,4+0,15=4,55$

$b)12\frac{1}{4}-6,7=12,25-6,7=12,25-6-0,7=6,25-0,7=5,55$

$c)9,25-5\frac{1}{5}=9,25-5,2=4,05$ $c)9,25-5\frac{1}{5}=9,25-5,2=4,05$

$d)14\frac{4}{7}-2,75=14\frac{4}{7}-2\frac{3}{4}=14\frac{16}{28}-2\frac{21}{28}=13\frac{44}{28}-2\frac{21}{28}=11\frac{23}{28}$

$e)7\frac{2}{5}+3\frac{3}{4}-5,7=7,4+3,75-5,7=11,15-5,7=11,15-5-0,7=6,15-0,7=5,45$

$f)8\frac{1}{2}-6,32+2\frac{3}{8}=8\frac{1}{2}+2\frac{3}{8}-6,32=8,5+2,375-6,32=10,875-6,32=4,555$

$g)4,52-1,22+6\frac{1}{3}-1\frac{1}{7}=3,3+6\frac{1}{3}-1\frac{1}{7}=3\frac{3}{10}+6\frac{1}{3}-1\frac{1}{7}=3\frac{9}{30}+6\frac{10}{30}-1\frac{1}{7}=$

 

$=9\frac{19}{30}-1\frac{1}{7}=9\frac{133}{210}-1\frac{30}{210}=8\frac{103}{210}$

$h)\underline{5,68}-1\frac{3}{14}+\underline{2,12}-5\frac{9}{14}=7,8-1\frac{3}{14}-5\frac{9}{14}=7,8-6\frac{12}{14}=7\frac{8}{10}-6\frac{6}{7}=$

$=7\frac{56}{70}-6\frac{60}{70}=6\frac{126}{70}-6\frac{60}{70}=\frac{66}{70}=\frac{33}{35}$

$i)\underline{5,8}-5\frac{8}{9}+\underline{3,4}-3\frac{3}{27}=9,2-5\frac{8}{9}-3\frac{3}{27}=9,2-5\frac{8}{9}-3\frac{1}{9}=9,2-8\frac{9}{9}=9,2-9=0,2$