Răspuns :
Notam cu a,b,c cele trei numere
[tex]\bf Ma = \dfrac{a+b+c}{3}[/tex]
[tex]\bf \dfrac{a+b+c}{3}\cdot \dfrac{30}{100} = 12[/tex]
[tex]\bf \dfrac{a+b+c}{\not3}\cdot \dfrac{\not30}{\not100} = 12[/tex]
[tex]\bf \dfrac{a+b+c}{1}\cdot \dfrac{1}{10} = 12[/tex]
[tex]\bf \dfrac{a+b+c}{10}= 12[/tex]
[tex]\bf a+b+c= 10\cdot 12[/tex]
[tex]\boxed{\bf a+b+c = 120}[/tex]
Raspuns: suma celor trei numere este 120
Fie a,b,c-trei numere
30/100×(a+b+c)/3=12
3/10×(a+b+c)/3=12
(a+b+)/10=12
a+b+c=12×10
a+b+c=120