Odpowiedź:
[tex]1\frac{1}{4} + (-2\frac{1}{3} ) = \frac{5}{4} - 2\frac{1}{3} = \frac{5}{4} - \frac{7}{3} = -\frac{13}{12} = -1\frac{1}{12} \\\\8\frac{2}{3} + (-7\frac{2}{5}) = \frac{16}{3} - 7\frac{2}{5} = \frac{16}{3} - \frac{37}{5} = -\frac{31}{15} = -2\frac{1}{15} \\\\-4\frac{1}{2} + (-6\frac{1}{3}) = -4\frac{1}{2} - 6\frac{1}{3} = - (4\frac{1}{2} + 6\frac{1}{3}) = - ((4+6) + (\frac{1}{2} + \frac{1}{3} )) = - (10+\frac{5}{6}) = -10\frac{5}{6} \\\\[/tex][tex]-8\frac{2}{5} + (-2\frac{1}{3})= -8\frac{2}{5} - 2\frac{1}{3} = -(8\frac{2}{5} + 2\frac{1}{3}) = -((8+2) + (\frac{2}{5} + \frac{1}{3})) = - (10+ \frac{11}{15} = -10\frac{11}{15} \\\\14\frac{2}{5} + (-15\frac{1}{2} ) = \frac{72}{5} - 15\frac{1}{2} = \frac{72}{5} - \frac{31}{2} = -\frac{11}{10}[/tex]
