Question

整体性代入例如：代数式X²+X-1的值为1,则代数式2-3X²-3X的值应为

Answer 1

2-3X²-3X

=-(-2+3X²+3X)

=-(1-3+3X²+3X)

=-(1+3(X²+X-1))

=-(1+3)

=-4