ПРОШУ помогите пожалуйста!!! номер 48 и 49

[latex] \frac{1}{4} + \frac{1}{6} = \frac{3}{12} + \frac{2}{12} = \frac{5}{12} [/latex] [latex]- \frac{1}{4} - \frac{1}{6} = - \frac{3}{12} - \frac{2}{12} =- \frac{5}{12} [/latex] [latex]- \frac{1}{4} + \frac{1}{6} = - \frac{3}{12} + \frac{2}{12} = - \frac{1}{12}[/latex] [latex]- \frac{1}{4} + \frac{1}{6} = - \frac{3}{12} + \frac{2}{12} = - \frac{1}{12} [/latex] № 49 [latex] \frac{11}{15} + \frac{9}{10} = \frac{22}{30} + \frac{27}{30} = \frac{49}{30} = 1\frac{19}{30} [/latex] [latex]- \frac{11}{15} - \frac{9}{10} = - \frac{22}{30} - \frac{27}{30} = - \frac{49}{30} =-1 \frac{19}{30} [/latex] [latex] \frac{11}{15} - \frac{9}{10} = \frac{22}{30} - \frac{27}{30} = - \frac{5}{30} = -\frac{1}{6} [/latex] [latex] -\frac{11}{15} + \frac{9}{10} = - \frac{22}{30} + \frac{27}{30} = \frac{5}{30} = \frac{1}{6} [/latex]