\(P\left(x\right)=x^{99}-100x^{98}+100x^{97}-100x^{96}+...+100x-1\)

\(\Leftrightarrow P\left(x\right)=x^{99}-100x^{98}+100x^{97}-100x^{96}+...+100x-1\)

\(\Leftrightarrow P\left(x\right)=x^{99}-99x^{98}-x^{98}+99x^{97}+x^{97}-...+99x+x-1\)

\(\Leftrightarrow P\left(x\right)=x^{98}\left(x-99\right)-x^{97}\left(x-99\right)+...+\left(x-1\right)\)

\(\Leftrightarrow P\left(x\right)=x^{98}\left(x-99\right)-x^{97}\left(x-99\right)+...+\left(99-1\right)\)

\(\Leftrightarrow P\left(99\right)=x^{98}\left(99-99\right)-x^{97}\left(99-99\right)+...+98\)

\(\Leftrightarrow P\left(99\right)=x^{98}.0-x^{97}.0+...+98\)

\(\Leftrightarrow P\left(99\right)=98\)

Tham khảo:

Câu hỏi của Bích Ngọc - Toán lớp 7 | Học trực tuyến

Học tốt

8)4(x-2)-2(x-1)=12

4x-8-(2x-2)=12

4x-8-2x+2=12

2x-8+2=12

2x=12-2+8

2x=18

x=18/2=9

9)6x-13-2-(x×5)=7

6x-5x=7+13+2

x=22

10)7(x-5)-3(x+5)=30

7x-35-(3x+15)=30

7x-35-3x-15=30

4x=30+35+15

4x=80

x=20

8)4(x-2)-2(x-1)=12

\(\Rightarrow4x-8-2x+2=12\)

\(\Rightarrow2x=18\)

\(=>x=9\)

9)6x-13-2-(x×5)=7

\(\Rightarrow6x-15-\left(x+5\right)=7\)

\(\Rightarrow6x-15-x-5=7\)

\(\Rightarrow5x=27\)

\(\Rightarrow x=\frac{27}{5}\)

10)7(x-5)-3(x+5)=30

\(\Rightarrow7x-35-3x-15=30\)

\(\Rightarrow4x=80\)

\(\Rightarrow x=20\)

 \(3x+5\)\(⋮\)\(2x+1\)

\(\Leftrightarrow2\left(3x+5\right)\)\(⋮\)\(2x+1\)

\(\Rightarrow6x+10\)\(⋮\)\(2x+1\)

\(\Rightarrow3\left(2x+1\right)+7\)\(⋮\)\(2x+1\)

\(\Leftrightarrow7\)\(⋮\)\(2x+1\)

\(\Rightarrow2x+1\inƯ_7\)Mà \(Ư_7=\left\{\pm1;\pm7\right\}\)

\(\Rightarrow...\)

thank bạn nha

* \(6x+3-2\left(x-5\right)=30\)

\(\Rightarrow6x+3-2x+10=30\)

\(\Rightarrow4x=17\Leftrightarrow x=\frac{17}{4}\)

* \(8\left(x-\frac{1}{8}\right)-5\left(x-\frac{1}{5}\right)=10\)

\(\Rightarrow3\left(x-\frac{1}{5}\right)=10\)

\(\Rightarrow x-\frac{1}{5}=\frac{10}{3}\)

\(\Rightarrow x=\frac{10}{3}+\frac{1}{5}=\frac{53}{15}\)

* \(13x-5-2\left(x+3\right)=1\)

\(\Rightarrow13x-5-2x-6=1\)

\(\Rightarrow11x=12\Leftrightarrow x=\frac{12}{11}\)

\(1,5x+2\left(x+\frac{1}{2}\right)=7\)

\(\Rightarrow5x+2x+1=7\)

\(\Rightarrow7x=6\)

\(\Rightarrow x=\frac{6}{7}\)

\(2,8x-3\left(x+2\right)=9\)

\(8x-3x-6=9\)

\(5x=15\)

\(x=3\)

\(a,\frac{\sqrt{108x^3}}{\sqrt{12x}}=\frac{\sqrt{36.3.x^3}}{\sqrt{3.4.x}}=\frac{6\sqrt{3}.\sqrt{x}^3}{2\sqrt{3}.\sqrt{x}}=3\sqrt{x}^2=3x\)

\(b,\frac{\sqrt{13x^4y^6}}{\sqrt{208x^6y^6}}=\frac{\sqrt{13}.\sqrt{x^4}.\sqrt{y^6}}{\sqrt{16.13}.\sqrt{x^6}.\sqrt{y^6}}=\frac{\sqrt{13}.x^2y^3}{4\sqrt{13}x^3y^3}=\frac{1}{4x}\)

\(c,\frac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\left(\sqrt{x}+\sqrt{y}\right)^2\)

\(=\frac{\sqrt{x}^3+\sqrt{y}^3}{\sqrt{x}+\sqrt{y}}-\left(x+2\sqrt{xy}+y\right)\)

\(=\frac{\left(\sqrt{x}+\sqrt{y}\right)\left(x-\sqrt{xy}+y\right)}{\sqrt{x}+\sqrt{y}}-x-2\sqrt{xy}-y\)

\(=x-\sqrt{xy}+y-x-2\sqrt{xy}-y=-3\sqrt{xy}\)

\(d,\sqrt{\frac{x-2\sqrt{x}+1}{x+2\sqrt{x}+1}}=\frac{\sqrt{\left(\sqrt{x}-1\right)^2}}{\sqrt{\left(\sqrt{x}+1\right)^2}}=\frac{\sqrt{x}-1}{\sqrt{x}+1}\)

Đk chỗ này là \(\sqrt{x}-1\ge0\Rightarrow\sqrt{x}\ge\sqrt{1}\Rightarrow x\ge1\)nhé 

\(e,\frac{x-1}{\sqrt{y}-1}.\sqrt{\frac{\left(y-2\sqrt{y}+1\right)^2}{\left(x-1\right)^4}}=\frac{x-1}{\sqrt{y}-1}.\frac{y-2\sqrt{y}+1}{\left(x-1\right)^2}\)

\(=\frac{\left(x-1\right)\left(\sqrt{y}-1\right)^2}{\left(\sqrt{y}-1\right)\left(x-1\right)^2}=\frac{\sqrt{y}-1}{x-1}\)

\(a,3x\left(x-\frac{2}{3}\right)=0 \)
\(\)TH1:
3x=0
x=0:3
x=0
       TH2
\(x-\frac{2}{3}=0 \)
\(x=0+\frac{2}{3}=\frac{2}{3}\)
Vậy x={0;\(\frac{2}{3}\)}

34 +14 :x=25 

\(\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)

NX: A > 0 

\(Ax^2=x^2-2x+3\)

\(\Leftrightarrow x^2\left(A-1\right)+2x-3=0\)

*A = 1

*A Khác 1 

Có ngiệm \(\Delta'\ge0\Leftrightarrow1+3\left(A-1\right)\ge0\Leftrightarrow3A\ge2\Leftrightarrow A\ge\frac{2}{3}\)

'=' tại x = 3