Question

-x²+25x-150

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Answer 1

\(-x^2+25x-150=-\left(x^2-25x+\dfrac{625}{4}\right)+\dfrac{625}{4}-150=\dfrac{25}{4}-\left(x-\dfrac{25}{2}\right)^2=\left(\dfrac{5}{2}-x+\dfrac{25}{2}\right)\left(\dfrac{5}{2}+x-\dfrac{25}{2}\right)=\left(15-x\right)\left(x-10\right)\)

Answer 2

`-x^2+25x-150`

`=-(x^2-25x+150)`

`=-(x^2-10x-15x+150)`

`=-[x(x-10)-15(x-10)]`

`=-(x-10)(x-15)`