tim x,y,z biet 4/x+1=2/y-2=3/z+2 va xyz=12
tim x,y,z biet x3/8=y3/27=z3/125 va xyz=810
CMR;3^x+1+3^x+2+...+3^x+100 chia het cho 120
Cho biet xyz=1
Tinh gia tri A=x/xy+x+1+y/yz+y+1+z/xz+z+1
Tìm x,y,z biet ax=by=cz va xyz=8/abc
cho biet xyz=1.tinh gia tri cua A=\(\frac{x}{xy+x+1}+\frac{y}{yz+y+1}+\frac{z}{xz+z+1}\)
tim xyz biet x2/4=y2/9=z2/25 va x-y+z=4
Tim cac so x , y , z biet : ax = by = cz va xyz = 8 / abc ( a, b ,c khac 0 )
tìm x,y, z nguyên thỏa mãn
x^3 + xyz = 957
y^3 + xyz = 759
z^3 + xyz = 579
tính xyz/x+y+z biết (x+y):(8-z):(y+z):(10+z)=2:5:3:4