→ introduc intregii in fractie
3intregi si 1 / 3 = ( 3 x 3 + 1 ) / 3 = 10 / 3
( x / 3 - 3 ) · 5 + (3 / 10) · ( 10 / 3 ) · 10 = 30
( x / 3 - 3 ) · 5 + 1 · 10 = 30
( x / 3 - 3 ) · 5 = 30 - 10
x / 3 - 3 = 20 : 5
x / 3 - 3 = 4
x / 3 = 4 + 3
x / 3 = 7
x = 3 · 7
x = 21
Verific:
( 21 / 3 - 3 ) · 5 + ( 30 / 30 ) · 10 = 30
= ( 7 - 3 ) · 5 + 10 =
= 4 · 5 + 10 =
= 20 + 10 =
= 30
