\(\frac{x^{10}-x^8-x^7+x^6+x^6+x^4-x^3-x^2+1}{x^{30}+x^{24}+x^{18}+x^{12}+x^6+1}=\frac{(x^{10}-x^8+x^6)-(x^7-x^5+x^3)+(x^4-x^2+1)}{ (x^{30}+x^{18}+x^{24})+(x^{12}+x^6+1)} \)

=\(\frac{(x^4-x^2+1)(x^6-x^3+1)}{(x^{12}+x^6+1)(x^{18}+1 )}=\frac{(x^4-x^2+1)(x^6-x^3+1)}{(x^{12}+2x^6+1-x^6) (x^6+1)(x^{12}-x^6+1)}=\frac{(x^4-x^2+1)(x^6-x^3+1)}{ (x^6-x^3+1)(x^6+x^3+1)(x^2+1)(x^4-x^2+1)(x^12-x^6+1 )} \)

=\(\frac{1}{(x^6+x^2+1)(x^2+1)(x^{12}-x^6+1)}\)

c) \(\dfrac{x-4\sqrt{x}+4}{x-2\sqrt{x}}\left(đk:x>0\right)=\dfrac{\left(\sqrt{x}-2\right)^2}{\sqrt{x}\left(\sqrt{x}-2\right)}=\dfrac{\sqrt{x}-2}{\sqrt{x}}\)

d) \(\dfrac{x-9}{x+6\sqrt{x}+9}\left(đk:x\ge0\right)=\dfrac{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}{\left(\sqrt{x}+3\right)^2}=\dfrac{\sqrt{x}-3}{\sqrt{x}+3}\)

e) \(\dfrac{x-10\sqrt{x}+25}{25-x}\left(đk:x\ge0,x\ne25\right)=\dfrac{\left(\sqrt{x}-5\right)^2}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}=\dfrac{\sqrt{x}-5}{\sqrt{x}+5}\)

c: \(\dfrac{x-4\sqrt{x}+4}{x-2\sqrt{x}}=\dfrac{\sqrt{x}-2}{\sqrt{x}}\)

d: \(\dfrac{x-9}{x+6\sqrt{x}+9}=\dfrac{\sqrt{x}-3}{\sqrt{x}+3}\)

e: \(\dfrac{x-10\sqrt{x}+25}{25-x}=\dfrac{5-\sqrt{x}}{\sqrt{x}+5}\)

Tham khảo:

a) \(P(x) = 9{x^4} + 8{x^3} - 6{x^2} + x - 1 - 9{x^4} = (9{x^4} - 9{x^4}) + 8{x^3} - 6{x^2} + x - 1 = 8{x^3} - 6{x^2} + x - 1\).

b) Số mũ cao nhất của x trong dạng thu gọn của P(x) là 3.

Mk làm luôn nhé , không chép lại đề đâu

Q = \(\dfrac{x^6\left(x^4-x^2+1\right)-x^3\left(x^4-x^2+1\right)+x^4-x^2+1}{x^{18}\left(x^{12}+x^6+1\right)+x^{12}+x^6+1}\)

\(Q=\dfrac{\left(x^4-x^2+1\right)\left(x^6-x^3+1\right)}{\left(x^{12}+x^6+1\right)\left(x^{18}+1\right)}\)

\(Q=\dfrac{\left(x^4-x^2+1\right)\left(x^6-x^3+1\right)}{\left(x^{12}+x^6+1\right)\left[\left(x^6\right)^3+1\right]}\)

\(Q=\dfrac{\left(x^4-x^2+1\right)\left(x^6-x^3+1\right)}{\left(x^{12}+2x^6+1-x^6\right)\left[\left(x^2\right)^3+1\right]\left(x^{12}-x^6+1\right)}\)

\(Q=\dfrac{\left(x^4-x^2+1\right)\left(x^6-x^3+1\right)}{\left[\left(x^6+1\right)-\left(x^3\right)^2\right]\left(x^2+1\right)\left(x^4-x^2+1\right)\left(x^{12}-x^6+1\right)}\)

\(Q=\dfrac{\left(x^6-x^3+1\right)}{\left(x^6-x^3+1\right)\left(x^6+1+x^3\right)\left(x^2+1\right)\left(x^{12}-x^6+1\right)}\)

\(Q=\dfrac{1}{\left(x^6+1+x^3\right)\left(x^2+1\right)\left(x^{12}-x^6+1\right)}\)

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