\(x=7\Rightarrow\left\{{}\begin{matrix}4=x-3\\20=3x-1\end{matrix}\right.\)\(\Rightarrow P\left(7\right)=x^{100}-4x^{99}-20x^{98}-4x^{97}-...-20x^2-4x\\ =x^{100}-\left(x-3\right)x^{99}-\left(3x-1\right)x^{98}-\left(x-3\right)x^{97}-...-\left(3x-1\right)x^2-\left(x-3\right)x\\ =x^{100}-x^{100}+3x^{99}-3x^{99}+x^{98}-x^{98}+3x^{97}-...-3x^3+x^2-x^2+3x\\ =3x\\ =21\)
Tìm x
\(\left(x+1\right)^2=4x^2+20x+25\)
thực hiện phép tính
a.\(2x^2\left(3x^2-7x-3\right)\)
b.\(\left(16x^4-20x^2y^3-4x^5y\right):\left(-4x^2\right)\)
\(\dfrac{15x\left(x+5\right)}{20x^2\left(x+5\right)}\)
\(\dfrac{x^3-4x^2}{y\left(x-4\right)}\)
\(\dfrac{5\left(a-2c\right)^2}{2a^2-4ac}\)
Bài 3: Tìm x, biết:
a, \(x^3-16x=0\)
b, \(x^4-2x^3+10x^2-20x=0\)
c, \(\left(2x-3\right)^2=\left(x+5\right)^2\)
d, \(x^2\left(x-1\right)-4x^2+8x-4=0\)
a)x(x-5)=4x-20
b)4(x+6)-x\(^3-6x^2=0\)
c)x\(^3-5x^2+x-5=0\)
d)\(x^4-2x^3+10x^2-20x=0\)
e)\(\left(2x-3\right)^2=9\left(x-2^2\right)\)
Bài 3 : Giải các phương trình sau bằng cách đưa về dạng ax+b=0 :
a) \(\frac{7}{8}x-5\left(x-9\right)=\frac{20x+1,5}{6}\)
b) \(4\left(0,5-1,5x\right)=-\frac{5x-6}{3}\)
c) \(\frac{x+4}{5}-x+4=\frac{x}{3}-\frac{x-2}{2}\)
d) \(\frac{4x+3}{5}-\frac{6x-2}{7}=\frac{5x+4}{3}+3\)
e) \(\frac{1}{4}\left(x+3\right)=3-\frac{1}{2}\left(x+1\right)-\frac{1}{3}\left(x+2\right)\)
Giaỉ PT
a) \(\left(\frac{x-1}{99}+x-99\right)+\left(\frac{x-3}{97}+\frac{x-7}{93}\right)+\left(\frac{x-5}{95}+\frac{x-95}{5}\right)=6\)
b) \(\left(4x-5\right)^2\left(2x-3\right)\left(x-1\right)=9\)
c) \(\frac{5}{x-8}+1=\frac{23}{x^2-5x-24}-\frac{2}{x+3}\)
Help !!
Tìm x
a) x^3 - 16x = 0
b) x^4 - 2x^3 + 10x^2 - 20x = 0
c) (2x - 3 )^2 = (x+5)^2
d) x^2(x-1) - 4x^2 + 8x - 4 = 0
e) x^2 + 4x + 3 = 0
f) x^3 - x^2 = 4x^2 - 8x + 4
g) 2(x+3) - x^2 - 3x = 0
Tìm x, biết:
a) \(5x\left(x-3\right)^2-5\left(x-1\right)^3+15\left(x+2\right)\left(x-2\right)=5\)
b) \(\left(x+2\right)\left(3-4x\right)=x^2+4x+4\)
