Question

当x平方+x=1时 求2x(x的²-2x-3分之1)+4(x²+12分之1x)-3分之1x(3x

Answer 1

2x(x2-2x-1/3)+4(x2+x/12) - x/3(3x2-6x-1)

=2x3-4x2-2x/3+4x2+x/3-x3+2x2+x/3

=x3+2x2 =x2(x+2)

= (1-x)(x+2) = -(x-1)(x+2)

= -(x2+x-2)

= 1