tim x;y thuoc n sao cho:
36-y^2=8[x-2010]^2
Tim cac gia tri x, y thoa man:
a, ( x2 - 1 ) ( x2 - 16 ) < 0 ca x thuoc z
b, 1/x - y/8 = 1/16 va x, y thuoc N
c, | x+1 | + | x+2 | + | x+3 | = x
tim cac gia tri x y thoa man
a,(x^2-1)(x^2-16)<0 va x thuoc Z
B,1/x-y/8=1/16 va x y thuoc N
tim x,y thuoc N* biet 1+x+x^2+x^3=2^y
tim x, y thuoc N biet:
1! + 2! +3! +....+ x! = y2
tim x,y thuoc N* sao cho 8x^3+y^3-6xy+1 la SNT
tim x, y thuoc N de 1! + 2! + ... + x! = y!
bai 1 cmr
a)n^3+11n chia het cho 6 voi moi n thuoc Z
b)mn(m^2-n^2)chia het cho 3 voi moi m,n thuoc Z
bai 2 tim x,y thuoc Z
a)(x-1)(3-y)=(-7)
help me
Tim x,y thuoc N*,biet: 1/x+1/y=1/2