x=4,3+3 4/9+(-8 2/5)+2,84+(-5)+(-2 1/7)
43/10+31/9+(-38/5)+284/100-5+(-13/7)
387/90+310/90-38/5+284/100-5-13/7
697/90-38/5+284/100-5/1-13/7
697/90-684/90+284/100-5/1-13/7
13/90+284/100-5/1-13/7
130/900+2556/900-5/1-13/7
2686/900-5/1-13/7
2686/900-4500/900-13/7
-1814/900-13/7
-12698/6300-11700/6300
-24398/6300
-12199/3150