解当x≥1时,得x-1≥0,即f（x-1）=1此时不等式xf(x-1)≤1转化为x*1≤1即x≤1此时xf(x-1)≤1的解x=1当x＜1时,x-1＜0即f（x-1）=-1此时不等式xf(x-1)≤1转化为x*（-1）≤1即x≥-1即此时不等式xf(x-1)≤1的解为1≤x＜1故...