Goi cac phan thu 1 ; phan thu 2 ; phan thu 3 la a;b;c
a/3=b/2;b/3=c/5=>a/3=3b/6;2b/6=c/5=>a/9=b/6=c/10 va a+b+c=175
Ap dung tinh chat day ti so bang nhau :
a/9=b/6=c/10=a+b+c/9+6+10=175/25=7
Suy ra : a/9=7=>a=9.7=63
b/6=7=>b=7.6=42
c/10=7=>c=10.7=70
**** nhe