a/b=b/c=c/a=a+b+c/b+c+a=1
a/b=1=>a=b
b/c=1=>b=c
vậy a=b=c
a/b=b/c=c/a=a+b+c/b+c+a=1
a/b=1=>a=b
b/c=1=>b=c
vậy a=b=c
cho 2/a=1/b+1/c(a,b,c khac 0,a khac c).Chung minh rang b/c=b-a/a-c
chung minh rang tu ti le thuc a/b=c/d (a-b khac 0,c-d khac 0) ta co the suy ra ti le thuc a+b/a-b=c+d/c-d
chung minh rang tu ti le thuc a/b=c/d (a-b khac 0,c-d khac 0) ta co the suy ra ti le thuc a+b/a-b=c+d/c
ai giai nhanh va dung cho toi hieu toi se tich nguoi do
cho ti le thuc voi a,b,c,d thuoc z b,d khac 0 chung minh rang a^2 + b^2 phần c^2 + d^2 =a*b phần c*d
Cho a = b + c va c = bd/b -d ( b , d khac 0 ) .chung minh rang a/b = c/d
cho a,b,c la 3 so thuc doi mot khac nhau va khac khong, thoa man: a+1/b=b+1/c=c+1/a. hay chung minh rang abc=1 hoac abc=-1
cho 3 so a,b,c khac thuoc Q khac nhau tung doi mot va khac 0 thoa man a/b+c=b/a+c=c/a+b
Chung minh b+c/a+a+c/b+a+b/c khong phu thuoc vao cac gia tri cua a,b,c
chung minh rang neu a,b,c la cac so khac 0 thoa man
ab+ac/2=bc+ba/3=ca+cb/4 thi a/3=b/5=c/15
cho so huu ti a/b va c/d voi b>0 chung to rang neu a/b > c/d thì a/b<a+c/b+d <c/d