Вправи 901 - 1050 » 1039

Обчисли: а) 1/5 + 2/5 = 3/5; б) 7/8 – 3/8 = 5/8; в) 2/7 + 2/7 = 4/7; г) 5/9 – 3/9 = 2/9; ґ) 1/6 + 5/6 = 6/6 = 1; д) 5/13 + 4/13 = 9/13; е) 2/9 + 7/9 = 9/9 = 1; є) 19/12 – 17/12 = 2/12.