Răspuns:
a) 2/7+(-4/21)=3×2+(-4)×1/21=2/21
b) (-7/5)+(-2/15)=3×(-7)+1×(-2)/15=-23/15
c) 1/6+(-3/4)=4×1+5×(-3)/24=-14/24sau-7/12
d) (-5/12)+(-3/4)=1×(-5)+3×(-3)/12= =-14/12sau-7/6
e) (-17/18)+(-2/6)=1×(-17)+3×(-2)/18=-23/18
f) (-1/6)+21/24=4×(-1)+1×21=17/24
g)(-3/10)+7/6=5×2+3×7/2=6/2sau3
h)2/15+(-7/18)=5×2+6×(-7)/3=-32/3
i)2/3+5/27=9×2+1×5/27=23/27
sper că te-am ajutat
