[tex]a)\\\\(-3,4)+6\frac{3}{4}+ 1\frac{1}{3}+(-0,6)+(- \frac{1}{3})+(-0,75) =\\\\\\= -3 \frac{4}{10} +6\frac{3}{4}+ 1\frac{1}{3} -\frac{6}{10}- \frac{1}{3} - \frac{75 }{100}= -3 \frac{2}{5} +6\frac{3}{4}+ 1\frac{1}{3} -\frac{3}{5}- \frac{1}{3} - \frac{3 }{4}=\\\\\\=( -3 \frac{2}{5} -\frac{3}{5})+(6\frac{3}{4}- \frac{3 }{4}) + (1\frac{1}{3}- \frac{1}{3} ) = -3\frac{5}{5}+6+1=-4+7=3[/tex]
[tex]b)\\\\ 2,75+(- 1\frac{3}{7})+4,2+(- \frac{4}{7})+ \frac{1}{4}+(-1,2)=\\\\\\=2\frac{ 75}{100} - 1\frac{3}{7} +4 \frac{2}{10} - \frac{4}{7} + \frac{1}{4} -1\frac{2}{10}=\\\\\\= 2\frac{ 3}{4} - 1\frac{3}{7} +4 \frac{1}{5} - \frac{4}{7} + \frac{1}{4} -1\frac{1}{5}=\\\\\\= (2\frac{ 3}{4}+\frac{1}{4})+ (- 1\frac{3}{7}-\frac{4}{7}) +(4 \frac{1}{5} -1\frac{1}{5} )=\\\\\\=2\frac{4}{4}-1\frac{7}{7}+3=3-2+3=4[/tex]
