Răspuns
21/15 * 3/7 = 3/5(am simplificat 15 cu 3 si 21 cu 7)
21/15 : 7/5 = 21/15 * 5/7 = 3/3= 1
(7/9+4/3):(3.1/2 - 1.3/5)
(pe 4/3 il amplificam cu 3)
(7/9 + 3*4/3*3):(31/10/2 - 13/10/5)
3.1= 31/10
1.3= 13/10
(7+12/9):( 31/10 * 2 - 13/10 * 5)
(19/9) : (31/5 - 13/2)
(19/9) : (31*2/10 - 13*5/10)
(19/9) : (62/10 - 65/10)
(19/9) : (-3/10)
10/9 * 10/-3
100/-27
Sper ca e asa.