已知x^2+8x-6=0,求x(x+1)(x+7)(x+8)的值
问题描述:
已知x^2+8x-6=0,求x(x+1)(x+7)(x+8)的值
答
x(x+1)(x+7)(x+8)
=x(x+8) (x+1)(x+7)
=(x²+8x) (x²+8x+7)
=6×(6+7)
=78