Aflati numarul natural x , astfel incat fiecare dintre urmatoarele egalitati sa fie adevatate: a) 3/5=x/10. b) 7/x=21/15. c) x+2/x+7=3x+6/48. ("/" inseamna supra)
produsul mezilor =produsul extremilor a) 3/5=x/10→5*x=3*10→x=30/5→x=6 b) 7/x=21/15→21x=7*15→x=105/21→x=5 c) (x+7)(3x+6)=48(x+2)→3x^2+6x+21x+42=48x+96→3x^2+27x-48x=96-42→3x^2-21x=54→ x(3x-21)=54→x=9
