notam nr cu a,b,c
media aritmetica:
[tex] \frac{a + b + c}{3} = 16 \\ a + b + c = 16 \times 3 \\ a + b + c = 48[/tex]
{a,b,c} d.p. {4,5,7}
[tex] \frac{a}{4} = \frac{b}{5} = \frac{c}{7} = k [/tex]
k-coeficient de proportionalitate
[tex] \frac{a}{4 } = k = > a = 4k[/tex]
[tex] \frac{b}{5} = k = > b = 5k[/tex]
[tex] \frac{c}{7} = k = > c = 7k[/tex]
a+b+c=48
4k+5k+7k=48
16k=48
k=48:16
k=3
a=4k=>a=4×3=>a=12
b=5k=>b=5×3=>b=15
c=7k=>c=7×3=>c=21
