dau 18 puncte pt rezolvare corecta si deasemenea si coroana ...vreau ajutor sunt a5a !!

Răspuns:
a) 50/50
b)19/5-13/10-4/15=
19x6/5x6-13x3/10x3-4x2/15x2=
114/30-39/30-8/30=
numitorul 30 si se scad numaratorii
c)10/11x11/12-1/2x4/10=
5/6-2/10=
5x5/6×5-2×3/10×3=
25/30-6/30=
19/30