cho x,y,z la cac so nguyen duong va x+y+z la so le, cac so thuc a,b,c thoa man (a-b)/x=(b-c)/y=(a-c)/z. chung minh rang a=b=c

Cho cac so nguyen duong a b c thoa man 

(a+1)^3+(b+2)^3+(c+3)^3=3(a+1)(b+2)(c+3)

tim cac so nguyen duong a,b,c thoa man a+b+c=91 va b^2=a*c

cho cac so nguyen duong a,b,c , d thoa man ab=cd. Chung minh:

A=\(a^{2008}+b^{2008}+c^{2008}+d^{2008}\) la hop so

cho a,b,c,x,y,z la cac so nguyen duong thoa man a^x=bc;b^y=ac;c^z=ab. chung minh xyz-x-y-z=2

Cho a, b, c, d la cac so nguyen duong  thoa man a²+b²=b²+d². CM a+b+c+d la hop so

Tim cac so nguyen duong a, b, c thoa man: \(\left\{{}\begin{matrix}\sqrt{a-b+c}=\sqrt{a}-\sqrt{b}+\sqrt{c}\\\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=1\end{matrix}\right.\)

cho a,b,c,d la cac so nguyen duong doi 1 khac nhau thoa man a/a+b  +   b/b+c   +  c/c+d  + d/d+a   =2

CMR abcd la 1 so chinh phuong

cho 3 so a,b,c la so nguyen . Trong do co 1 so nguyen am , 1 so nguyen duong va 1 so bang 0 , thoa man IaI=b^2.(b-c) . Hoi a,b,c thuoc loai so nao