Вправи для повторення розділу 1 » 30

Знайди значення виразу: 1) 7/10 + 3/а, якщо а = 5; 10; 15; 20; 30; 45; 7/10 + 3/5 = (7 + 6)/10 = 13/10 = 13/10; 7/10 + 3/10 = (7 + 3)/10 = 10/10 = 1; 7/10 + 3/15 = (21 + 6)/30 = 27/30; 7/10 + 3/20 = (14 + 3)/20 = 17/20; 7/10 + 3/30 = (21 + 3)/30 = 24/30 = 12/15; 7/10 + 3/45 = (63 + 6)/90 = 69/90 = 23/30; 2) х/16 – 1/х, якщо х = 2; 4; 6; 8; 10; 12; 2/16 – 1/2 = (1 - 4)/8; 4/16 – 1/4 = (1 - 1)/4 = 0; 6/16 – 1/6 = (18 - 8)/48 = 10/48 = 5/24; 8/16 – 1/8 = (8 - 2)/16 = 6/16 = 3/8; 10/16 – 1/10 = (50 - 8)/80 = 42/80 = 21/40; 12/16 – 1/12 = (36 - 4)/48 = 32/48 = 2/3;