stiu decat la 3 pentru ca si eu am aceeasi carte si nici eu nu am stiut exercitiul 4 .
3. a) 5/12+5/24=10+5/24=15/24
b) 26/21+13/14=26*2+13/42=52+39/42=92/42=46/21=2 intregi 4/21
c) 4/15+3/20=16+9/60=25/60=5/12
d) 5/24+1/12+3/8=5+2+9/24=16/24=2/3
e) 7/30-3/20=7*2-3*3/60=14-9/60=5/60=1/12
f)8/15-9/20=4*8-3*9/60=32-27/60=5/60=1/12
g)8/21-4/32=8*5-4*3/105=40-12/105=28/105=4/15
h)7/6-3/4-1/12=7*2-3*3-1/12=14-9-1/12=4/12=1/3.
sper ca te-am ajutat daca nu înțelegi imi spui !!!
