Răspuns:
Explicație pas cu pas:
La operatiile cu fractii care nu au acelasi numitor, se face intai aducerea la acelasi numitor, apoi se fac operatiile.
a) 2/3+1/4=(4·2+3·1)/3·4=(8+3)/12=11/12
b) 11/12-1/2-1/6=(11-6·1-2·1)/12=(11-6-2)/12=3/12=3/3·4=1/4
c) 2/15+7/20+1 3/10=2/15+7/20+(1·10+3)/10=2/15+7/20+13/10=(4·2+3·7+6·13)/50=(8+21+78)/60=107/60
d) 7/48+1/30=(5·7+8·1)/240=(35+8)/240=43/240
e) 13/75-2/45=(3·13-5·2)225=(39-10)/225=29/225
f) 8/15-2/15=(8-2)/15=6/15=2/5
g) 3,2+(-1,2)=3,2-1,2=2
h) -1,5+(-3)=-1,5-3= -4,5
i) (+2,7)+(-3,7)=2,7-3,7= -1
j) -5,2+(-2,8)= -5,2-2,8= -8
