... ' tớchcỏcimOkhiA,B,C thayi. KthiIMOlnth4ư 1962 1.Tỡmstnhiờnnhnhtcúchscuicựngl6,saochonuscuicựngl 6cdichuynlờnuthỡ cmtsgp4lnsú. 2.Tỡmttccỏcsthcxthomón: (3 - x ) - (x + 1) > TuyntpcỏcthiIMO Page4 ... +1thỡtacúthlyM(n)=n n+1 TuyntpcỏcthiIMO Page31 KthiIMOlnth35ư1994 1.Chocỏcsnguyờndngm,n.Gia1,a2, ,am lcỏcphntkhỏcnhauca tp{1,2,3, ,n}saochovibtkỡa +a Ê n(vii,jnoú,c thi= j)tacú i j a +a =a viknoú. ... (b)Tỡmgiỏtrnhnhtcúthcatl V1 Trongtrnghpnyxõydnggúc V2 nacahỡnhnún. KthiIMOlnth3ư 1961 1.Giihphngtrỡnhsauvinx,y,z: TuyntpcỏcthiIMO Page3 ỡ x + y + z = a ù 2 2 x + y + z = b ù xy = z ợ Viiukinnocaa,bx,y,zlcỏcsdngkhỏcnhau?...