Question

配方的问题？

Answer 1

配方

-x+13.36√x +20.12

把-1 抽出

=-(x-13.36√x -20.12)

考虑 6.68^2=44.6224

=-(x-13.36√x +44.6224-64.7424)

变成

=-(x-13.36√x +44.6224)+64.7424

利用 x-13.36√x +44.6224 =(√x-6.68)^2

=-(√x-6.68)^2 +64.7424

Answer 2

=-(√x-6.8)²+6.8²+20.12
=-(√x-6.8)²+6.8²+20.12

=66.36-(√x-6.8)²
=(66.36+√x-6.8)(√66.36-√x+6.8)