Giúp tôi giải bài này với mn ơi

Giải thích các bước giải:

Ta có:

$\begin{cases}x_1+x_2=1\\x_1x_2=-1\end{cases}$

$P(x_1)-P(x_2)=(3x_1-\sqrt{33x_1+25})-(3x_2-\sqrt{33x_2+25})$

$\to P(x_1)-P(x_2)=3(x_1-x_2)-(\sqrt{33x_1+25}-\sqrt{33x_2+25})$

$\to P(x_1)-P(x_2)=3(x_1-x_2)-\dfrac{(33x_1+25)-(33x_2+25)}{\sqrt{33x_1+25}+\sqrt{33x_2+25}}$

$\to P(x_1)-P(x_2)=3(x_1-x_2)-\dfrac{33(x_1-x_2)}{\sqrt{33x_1+25}+\sqrt{33x_2+25}}$

$\to P(x_1)-P(x_2)=(x_1-x_2)(3-\dfrac{33}{\sqrt{33x_1+25}+\sqrt{33x_2+25}})$

Ta có:

$A=\sqrt{33x_1+25}+\sqrt{33x_2+25}$

$\to A^2=(\sqrt{33x_1+25}+\sqrt{33x_2+25})^2$

$\to A^2=33(x_1+x_2)+50+2\sqrt{(33x_1+25)(33x_2+25)}$

$\to A^2=33(x_1+x_2)+50+2\sqrt{33\cdot 25(x_1+x_2)+33^2x_1x_2+25^2}$

$\to A^2=33\cdot 1+50+2\sqrt{33\cdot 25\cdot 1+33^2\cdot (-1)+25^2}$

$\to A^2=121$

$\to A=11$

$\to P(x_1)-P(x_2)=(x_1-x_2)(3-\dfrac{33}{11})=0$

$\to P(x_1)=P(x_2)$