已知3x2+4x-7=0,则6x4+11x3-7x2-3x-7=_.
问题描述:
已知3x2+4x-7=0,则6x4+11x3-7x2-3x-7=______.
答
∵6x4+11x3-7x2-3x-7,
=6x4+8x3-14x2+3x3+4x2-7x+3x2+4x-7,
=2x2(3x2+4x-7)+x(3x2+4x-7)+(3x2+4x-7),
=(3x2+4x-7)(2x2+x+1),
又3x2+4x-7=0,
∴原式=0.