Se dau numerele naturale a,b,c,d astfel incat b=2a, 3b=2c, 4c=3d.
a) Stabiliti daca b² =ad;
b)
Aflati a,b,c,d stiind ca a+b+c+d=48

1
a,b,c,d imi dau cu "virgula"...
adica nu sunt numere naturale
Nu cred ca trebuie sa fie neaparat numere naturale
ok, gasesti mai jos raspunsul, eu am verificat rezultatele facand si proba...

Răspunsuri

2014-07-17T12:01:41+03:00
Stim ca b=2a, 3b=2c, 4c=3d.
a)
ad= \frac{b}{2} * \frac{4c}{3}   =   \frac{b}{2} * \frac{4}{3} * \frac{3b}{2}   = b²

b)a+b+c+d=48

c=  \frac{3b}{2}  \frac{3}{2} *2a = 3a

d= \frac{4}{3} c= \frac{4}{3} * \frac{3}{2} *b=2b=4a

=>a+ 2a+3a+4a=48
10a=48
a=4.8
b=9.6
c=14.4
d=19.2