Question

considere a=2/3 - 1.444... e b =0.7 - 0,777...
determine a : b

Answer 1

a=2/3-1,444....
1,444...
x=1,4444...
10x=14,444...
10x-x=14,444...-1,444...
9x=13
x=13/9

a=2/3-13/9
a=6/9-13/9
a=-7/9


b=0,7-0,7777....
0,7=7/10

0,7777...=
y=0,777...
10y=7,777...
10y-y=7,777...-0,777...
9y=7
y=7/9

b=7/10-7/9
b=63/90-70/90
b=-7/90

a:b=
-7/9:-7/90=
-7/9.-90/7=
-630/-63=
+10