Đề bài như này chứ nhỷ :-/ $17(xyzt+xy+xt+zt+1)=54(yzt+y+t)$
<=> $\frac{xyzt+xy+xt+zt+1}{yzt+y+t}=\frac{54}{17}$
<=> $x+\frac{zt+1}{yzt+y+t}=3+\frac{3}{17}$
==> $x=3 ; \frac{zt+1}{yzt+y+t}=\frac{3}{17}$
==> $\frac{yzt+y+t}{zt+1}=\frac{17}{3}$
<=> $y+\frac{t}{zt+1}=5+\frac{2}{3}$
==> $y=5 ; \frac{t}{zt+1}=\frac{2}{3}$
==> $t=2 ; z=1$
Vậy : $x=3 ; y=5 ; z=1 ; t=2$
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