1) 19-9*2* 1/2 - o,25*31+4
19-9-0,25*31+4
19-9-7,75+4=6,25
2)2,5+5*3/5 /(4,9*3,01-37/25 * 1/2)
2,5+5*3/5 (17,749- 37/25 * 1/2)
2,5+3/ (14,749-37/25 * 1/2)
5/2 + 3 / (14,749-37/25 * 1/2)
5/2 + 3 / (14749/1000 - 37/25 * 1/2)
5/2 + 3 / (14749/1000 - 37/50)
5/2 + 3 / 14009/1000
5/2 + 3 * 1000/14009
5/2 + 3000/14009
76045/28018
3) (2/3)^3 - (-1/2)^2 / (-2/3)^3
(3/2)^3 - (-1/2)^2 / (-(2/3)^3)
(3/2)^3 = (-1/2)^2) / (2/3)^3
27/8 + (-1/2)^2 / (2/3)^3
27/8 + (1/2)^2 / (2/3)^3
27/8 + (1/2)^2 + 8/27
27/8 + 1/4 / 8/27
27/7 + 1/4 / 27/8
27/8 + 27/32
135/32