Question

a+3,b+4,c+5 sunt direct proporționale cu 3,4,5 .Aflati nr a,b,si c daca a+b+c=60

Answer 1

(a+3)/3=(b+4)/4=(c+5)/5
4(a+3)=3(b+4), 4a+12=3b+12, 4a=3b, b=4a/3
5(a+3)=3(c+5), 5a+15=3c+15, 5a=3c, c=5a/3, inlocuim pe b si c in ultima ecuatie
a+b+c=60, a+4a/3+5a/3=60, numitor comun 3
3a+4a+5a=180, 12a=180, a=180/12=15
b=4a/3=4*15/3=60/3=20
c=5a/3=5*15/3=75/3=25