Сделайте деяния:(3/4+1/20)1/2; (7цел3/5-2цел4/15)9/32; (5цел1/2+2цел3/5)5/9.

1) (3/4 + 1/20) * 1/2 = (5 * 3/(4 * 5) + 1/20) * 1/2 = (15/20 + 1/20) * 1/2 = (15 + 1)/20 * 1/2 = 16/20 * 1/2 = 4/5 * 1/2 = 2/5;

Ответ: 2/5.

2) (7 3/5 - 2 4/15) * 9/32 = ((7 * 5 + 3)/5 - (2 * 15 + 4)/15) * 9/32 = (38/5 - 34/15) * 9/32 = (3 * 38/15 - 34/15) * 9/32 = (114 - 34)/15 * 9/32 = 80/15 * 9/32 = (80 * 9)/(15 * 32) = 3/2;

3) (5 1/2 + 2 3/5) * 5/9 = ((5 * 2 + 1)/2 + (2 * 5 + 3)/5) * 5/9 = (11/2 + 13/5) * 5/9 = (5 * 11/10 + 2 * 13/10) * 5/9 = (55/10 + 26/10) * 5/9 = (55 + 26)/10 * 5/9 = 81/10 * 5/9 = (81 * 5)/(10 * 9) = 9/2.