Выполните действие: 1) 7/12+ 7/20 2) 3/8+ 1/18 3) 1/12 +11/14 4) 2/15 -7/12 5) 9/14 - 5/12 6) 19/75 + 7/50

1) [latex] \frac{7}{12} [/latex] + [latex] \frac{7}{20} [/latex] = [latex] \frac{35 + 21 }{60} [/latex] = [latex] \frac{56}{60} [/latex] = [latex] \frac{14}{15} [/latex] 2) [latex] \frac{3}{8} [/latex] + [latex] \frac{1}{18} [/latex] = [latex] \frac{27 + 4}{72} [/latex] = [latex] \frac{31}{72} [/latex] Если нужно дальше, сделаю. 

1)7/12+7/20=35/60+21/60= 56/60=14/15 2)3/8+1/18=27/72+4/72= 31/72 3)1/12+11/14=7/84+66/84= 73/84 4)2/15-7/12=8/60-35/60= 27/60=9/20 5)9/14-5/12=54/84-35/84= 19/84 6)19/75+7/50=38/150+21/150=59/150