Математика 5 класс Никольский номер 1118 7/20×9+12×7/36+1 8/15÷4+3/5÷4 1/2
1. 7/20*9 = 63/20 2. 7/36*12 = 7/3 3. 1 8/15:4=23/15*1/4 = 23/60 4. 3/5:4 1/2=3/5:9/2 = 3/5*2/9=6/45 5. 63/20+23/60 = (189+23)/60=212/60 6. 7/3+6/45 = (105+6)/45 = 111/45 7. 212/60+111/45 = (636+444)/180 = 1080/180 = 6