1.证明:
2^48-1=(2^24+1)(2^24-1)
=(2^24+1)(2^12+1)(2^12-1)
=(2^24+1)(2^12+1)(2^6+1)(2^6-1)
=(2^24+1)(2^12+1)*65*63
则2的48次方减去1可以被63和65整除
2.分解因式;
x³-3x+2
=(x³-2x²+x)+2x²-4x+2
=x(x²-2x+1)+2(x²-2x+1)
=x(x-1)²+2(x-1)²
=(x-1)²(x+2)