1,

`9/5`, 1,4; véges; 4

`17/20`; 0,85; véges; 8

`4/9`; `0.dot(4)`; végtelen; 4


2,

`2/3+4/5-1` = `(10+12-15)/15` = `7/15`

`3/8*4-1/4` = `6/4-1/4` = `5/4` = `1 1/4`

`12/21*24/16` = `4/7*3/2` = `12/14` = `6/7`

`16/10:8+2/5` = `1/5+2/5` = `3/5`

`13/25:(26/30)` = `13/25*30/26` = `1/5*6/2` = `3/5`

`(2/7+3/4-1/2)*5` = `((8+21-14)/28)*5` = `15/28*5` = `75/28` = `2 19/28`

3,

a,

5x-25-2x = 2x+8

3x-25 = 2x+8

x = 33

b,

4(3-x)+21+7x = 2(x-3)+48

12-4x+21+7x = 2x-6+48

3x+33 = 2x+42

x = 9

c,

`x/12-(3x)/4+(5x)/6=2-(2x)/3`

`(x-9x+10x)/12=(24-8x)/12`

2x = 24-8x

10x = 24

x = 2,4

d,

`(x-1)/2+(x+1)/3=3/2`

`(3x-3+2x+2)/6=9/6`

5x-1 = 9

5x = 10

x = 2