Question

Fie numerele rationale a,b,c,d.Utilizati factorul comun si relatiile date:
c) Daca a = 4/9 ,b+c=15/8 si c-d=9/20 , calculati a*b+2*a*c-a*d

Answer 1

ab+ac=5/6

ac-ad=1/5

insumind cele doua relatii obtinem ab+2ac-ad=5/6+1/5=31/30