4/25+3/10= 7/9-5/12= 7/20+8/15= 6/7-3/5= 9/16+7/1= 3/4-11/18= 13/28-17/21= 13/35+5/42= 7/24+3/20= ЕСЛИ МОЖНО С ОБЬЯСНЕНИЯМИ

[latex] \frac{4}{25} + \frac{3}{10} = \frac{4*2+3*5}{50} = \frac{23}{50} [/latex] [latex] \frac{7}{9} - \frac{5}{12} = \frac{7*4-5*3}{36} = \frac{15}{36} = \frac{5}{12} [/latex] [latex] \frac{7}{20} + \frac{8}{15} = \frac{7*3+8*4}{60} = \frac{53}{60} [/latex] [latex] \frac{6}{7} - \frac{3}{5} = \frac{6*5-3*7}{35} = \frac{9}{35} [/latex] [latex] \frac{9}{16} + \frac{7}{1} = 7\frac{9}{16} [/latex] [latex] \frac{3}{4} - \frac{11}{18} = \frac{9*3-11*2}{36} = \frac{5}{36} [/latex] [latex] \frac{13}{28}- \frac{17}{21}= \frac{13*3-17*4}{84} =- \frac{29}{84} [/latex] [latex] \frac{13}{35} - \frac{5}{42} = \frac{13*6-5*5}{210} = \frac{53}{210} [/latex] [latex] \frac{7}{24}+ \frac{3}{20}= \frac{ 7*5+3*6}{120}= \frac{50}{120}= \frac{5}{12} [/latex]