Răspuns :
450 din 1 pe noua egal calculeaza du faci 450 imp la 9 ori 1 si dupa 450 la cat iti da
1 nr-x
2 nr-1/9 x
x+1/9x=450
1 intreg si 1/9x=450
10/9x=450
x=450/1:10/9
x=450*9/10
x=45*9
x=405
1 nr-405
2 nr-405:9=45
r-s:1 nr-405; 2 nr-45
405+45=450
2 nr-1/9 x
x+1/9x=450
1 intreg si 1/9x=450
10/9x=450
x=450/1:10/9
x=450*9/10
x=45*9
x=405
1 nr-405
2 nr-405:9=45
r-s:1 nr-405; 2 nr-45
405+45=450