Question

Rezolvati urmatoarele fractii
21/4-5/6+13/12
9/2+7/4-5/8
7/3+4/9-2/3
10/3-3/2-2/6
5/2-1/3-1/12

Answer 1

$\frac{21}{4}-\frac{5}{6}+\frac{13}{12}=\frac{21*3-5*2+13*1}{12}=\frac{63-10+13}{12}=\frac{66}{12}=\frac{11}{2}=5\frac{1}{2}\\\frac{9}{2}+\frac{7}{4}-\frac{5}{8}=\frac{9*4+7*2-5*1}{8}=\frac{36+14-5}{8}=\frac{45}{8}=5\frac{5}{8}\\\frac{7}{3}+\frac{4}{9}-\frac{2}{3}=\frac{7*3+4*1-2*3}{9}=\frac{21+4-6}{9}=\frac{19}{9}=2\frac{1}{9}\\\frac{10}{3}-\frac{3}{2}-\frac{2}{6}=\frac{10*2-3*3-2*1}{6}=\frac{20-9-2}{6}=\frac{9}{6}=\frac{3}{2}=1\frac{1}{2}$

$\frac{5}{2}-\frac{1}{3}-\frac{1}{12} =\frac{5*6-1*4-1*1}{12}=\frac{30-4-1}{12}=\frac{25}{12}=2\frac{1}{12}$

Answer 2

$a) \frac{21}{4} - \frac{5}{6} + \frac{13}{12} = \frac{21 \times 3}{4 \times 3} - \frac{5 \times 2}{6 \times 2} + \frac{13}{12} = \frac{63 - 10 + 13}{12} = \frac{66}{12} = \frac{11}{2} = 5 \frac{1}{2} \\ \\ b) \frac{9}{2} + \frac{7}{4} - \frac{5}{8} = \frac{9 \times 4}{2 \times 4} + \frac{7 \times 2}{4 \times 2} - \frac{5}{8} = \frac{36}{8} + \frac{14}{8} - \frac{5}{8} = \frac{36 + 14 - 5}{8} = \frac{45}{8} = 5 \frac{5}{8} \\ \\ c) \frac{7}{3} + \frac{4}{9} - \frac{2}{3} = \frac{7 \times 3}{3 \times 3} + \frac{4}{9} - \frac{2 \times 3}{3 \times 3} = \frac{21}{9} + \frac{4}{9} - \frac{6}{9} = \frac{21 + 4 - 6}{9} = \frac{19}{9} = 2 \frac{1}{9} \\ \\ d) \frac{10}{3} - \frac{3}{2} - \frac{2}{6} = \frac{10}{3} - \frac{3}{2} - \frac{1}{3} = \frac{10 \times 2 - 3 \times 3 - 2}{6} = \frac{20 - 9 - 2}{6} = \frac{9}{6} = \frac{3}{2} = 1 \frac{1}{2} \\ \\ e) \frac{5}{2} - \frac{1}{3} - \frac{1}{12} = \frac{5 \times 6}{2 \times 6} - \frac{1 \times 4}{3 \times 4} - \frac{1}{12} = \frac{30}{12} - \frac{4}{12} - \frac{1}{12} = \frac{30 - 4 - 1}{12} = \frac{25}{12} = 2 \frac{1}{12}$