Завдання 1601 - 1695 » 1633

Обчисли: 1) 21/8 + 33/4 = 17/8 + 15/4 = (17 + 30)/8 = 47/8 = 57/8; 2) 195/6 – 711/12 = 119/6 – 95/12 = (238 - 95)/12 = 143/12 = 1111/12; 3) –21/7 + 35/14 = –15/7 + 47/14 = (-30 + 47)/14 = 17/14 = 13/14; 4) 23/5 – 32/7 = 13/5 – 23/7 = (91 - 115)/35 = –24/35; 5) –41/3 – 57/9 = –13/3 – 52/9 = (-39 - 52)/9 = –91/9 = –101/9; 6) –51/8 – (–47/12) = –41/8 + 55/12 = (-123 + 110)/24 = –13/24;