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
cho doan thang AB va 2 diem M,N khong thuoc doan thang. Biet AM=MB, NA=NB.
chung to 2 diem M,N cung voi trung diem I cua AB la 3 diem thang hang
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
cho x thuộc q va 0<x<2 .CMR x^n <x voi n>=2
tim x,y thuoc N* biet 1+x+x^2+x^3=2^y
Tim x, y, z biet
a ) |x-3,5|+ |x+5|=0
b) |x-1| + (y+1)^2 + |z-1|=0
c) ( x-1/3)^2 + (y-2)^2+ (z-1)^2 be hon hoac bang 0
d)(x-z)^2+ (y+x)^2 + (z+1/4)^2 =0
Cac ban giup minh voi minh can gap lam
biet a+1 va 2a+1 (a thuoc N) dong thoi la 2 so chinh phuong. chung minh rang a chia het cho 24
Tim x,y thuoc N*,biet: 1/x+1/y=1/2