A(x)=x^4-123x^3-123x^2-123x-125 tính a(122)

1 bình luận về “A(x)=x^4-123x^3-123x^2-123x-125 tính a(122)”

1. $\text{Đặt x=122}$

   $\text{⇒$\left \{ {{123=x+1} \atop {125=x+3}} \right.$ }$

   $\text{⇒A(122)=$x^{4}$ -123$x^{3}$ +123$x^{2}$ -123x +125}$

                $\text{=$x^{4}$ -(x+1)$x^{3}$+(x+1)$x^{2}$ -(x+1)x+x+3}$

                $\text{=$x^{4}$ -$x^{4}$ – $x^{3}$ + $x^{3}$ – $x^{2}$ + $x^{2}$ – x + x + 3 }$

                $\text{=3}$

   $\text{Vậy A(122)=3}$

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