\(=\dfrac{1}{4}\left(x-4y\right)\left(x^2+4xy+16y^2\right)+4\left(4y^3-\dfrac{1}{16}x^3+1\right)\)
\(=\dfrac{1}{4}\left(x^3-64y^3\right)+4\left(4y^3-\dfrac{1}{16}x^3+1\right)\)
\(=\dfrac{1}{4}x^3-16y^3+16y^3-\dfrac{1}{4}x^3+4=4\)
Rút gọn, rồi tính giá trị các phân thức sau : A=\(\dfrac{\left(2x^{2^{ }}+2x^{ }\right)\left(x-2\right)^2}{^{ }\left(x^{3^{ }}-4x\right)\left(x+1\right)}\)với x = \(\dfrac{1}{2}\)
B=\(\dfrac{x^3-x^{2^{ }}y+xy^2}{x^3+y^3}\)với x = -5 , y = 10
Rút gọn phân thức :
a) \(\dfrac{x^4-y^4}{y^3-x^3}\)
b) \(\dfrac{\left(2x-4\right)\left(x-3\right)}{\left(x-2\right)\left(3x^2-27\right)}\)
c) \(\dfrac{2x^3+x^2-2x-1}{x^3+2x^2-x-2}\)
1. Rút gọn phân thức \(\dfrac{\left(x+y\right)^2}{x^2-y^2}=\) ta được kết quả là:
2. Rút gọn phân thức \(\dfrac{x^2-3x}{x^2-9}=\)
giúp mình với nhé mình đang cần gấp ạ
Rút gọn phân thức:
1, \(\dfrac{x^2+y^2-1+2xy}{x^2-y^2+1+2x}\)
2, \(\dfrac{x^4-y^4}{x^3+y^3}\)
3, \(\dfrac{x^3+y^3+z^3-3xyz}{\left(x-y\right)^2+\left(x-z\right)^2+\left(y-z\right)^2}\)
4, \(\dfrac{\left(x^2-y^2\right)^3+\left(y^2-z^2\right)^3+\left(z^2-x^2\right)^3}{\left(x-y\right)^3+\left(y-z\right)^3+\left(z-x\right)^3}\)
5, \(\dfrac{x^3-7x+6}{x^2\left(x-3\right)^2+4x\left(3-x\right)^2+4\left(x-3\right)^2}\)
Rút gọn các biểu thức sau :
a)\(\dfrac{25xy^3\left(2x-y\right)^2}{75xy^2\left(y-2x\right)}\)
b)\(\dfrac{x^2-y^2}{x^2-y^2+xz-yz}\)
c)\(\dfrac{\left(2x+3\right)-x^2}{x^2-1}\)
d)\(\dfrac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)
Rút gọn phân thức
a,\(\dfrac{\left(x^2-y\right).\left(y+1\right)+x^2y^2-1}{\left(x^2+y\right).\left(y+1\right)+x^2y^2+1}\)
b,\(\dfrac{x^2\left(y-z\right)+y^2\left(z-x\right)+z^2\left(x+y\right)}{x^2y-x^2z+y^2z-y^3}\)
c, \(\dfrac{x^3+3x^2-4}{x^3-3x+2}\)
d , \(\dfrac{x^4+6x^3+9x^2-1}{x^4+6x^3+7x^2-6x+1}\)
Rút gọn phân thức
1). \(\dfrac{x^4-y^4}{y^3-x^3}\)
2). \(\dfrac{\left(2x-4\right)\left(x-3\right)}{\left(x-2\right)\left(3x^2-27\right)}\)
3). \(\dfrac{2x^3+x^2-2x-1}{x^3+2x^2-x-2}\)
Rút gọn phân thức:
1.\(\dfrac{\left(x-y\right)^{3^{ }}-3xy\left(x+y\right)+y^3}{x-6y}\)
2. \(\dfrac{x^2+y^2+z^2-2xy+2xz-2yz}{x^2-2xy+y^2-z^2}\)
3.\(\dfrac{\left(n+1\right)!}{n!\left(n+2\right)}\)
4. \(\dfrac{n!}{\left(n+1\right)!-n!}\)
5. \(\dfrac{\left(n+1\right)!-\left(n+2\right)!}{\left(n+1\right)!+\left(n+2\right)!}\)
Rút gọn các phân thức :
a) \(\dfrac{14xy^5\left(2x-3y\right)}{21x^2y\left(2x-3y\right)^2}\)
b) \(\dfrac{8xy\left(3x-1\right)^3}{12x^3\left(1-3x\right)}\)
c) \(\dfrac{20x^2-45}{\left(2x+3\right)^2}\)
d) \(\dfrac{5x^2-10xy}{2\left(2y-x\right)^3}\)
e) \(\dfrac{32x-8x^2+2x^3}{x^3+64}\)
f) \(\dfrac{9-\left(x+5\right)^2}{x^2+4x+4}\)
g) \(\dfrac{80x^3-125x}{3\left(x-3\right)-\left(x-3\right)\left(8-4x\right)}\)
h) \(\dfrac{5x^3+5x}{x^4-1}\)
i) \(\dfrac{x^2+5x+6}{x^2+4x+4}\)
