(1)由kx=x+2,得(k-1)x=2.依题意k-1≠0.∴x= 2 k?1 .∵方程的根为正整数,k为整数,∴k-1=1或k-1=2.∴k1=2,k2=3.(2)依题意,二次函数y=ax2-bx+kc的图象经过点(1,0),∴0=a-b+kc,kc=b-a,∴ (kc)2?b2+ab akc = (b?a)2?b2+ab a(b?a) = b2?2ab+a2?b2+ab ab?a2 = a2?ab ab?a2 =?1.