Quy đồng mẫu các phân thức sau:
a)\(\dfrac{x}{x-y}\); \(\dfrac{y}{\left(x-y\right)^2}\) ; \(\dfrac{1}{\left(y-x\right)^3}\)
b) \(\dfrac{1}{2x+4};\dfrac{x}{2x-4};\dfrac{3}{4-x^2}\)
Quy đồng mẫu thức của các phân thức
1. \(\dfrac{x-y}{2x^2-4xy+2y^2};\dfrac{x+y}{2x^2+4xy+2y^2};\dfrac{1}{y^2-x^2}\)
2. \(\dfrac{1}{x^2+8x+15};\dfrac{1}{x^2+6x+9}\)
3. \(\dfrac{1}{\left(a-b\right)\left(b-c\right)};\dfrac{1}{\left(c-b\right)\left(c-a\right)};\dfrac{1}{\left(b-a\right)\left(a-c\right)}\)
Rút gọn các phân thức sau:
a) \(\dfrac{6x^2y^2}{8xy^{ }5}\)
b) \(\dfrac{10xy^2\left(x+y\right)}{15xy\left(x+y\right)^3}\)
c) \(\dfrac{2x^2+2x
}{x+1}\)
d) \(\dfrac{x^2-xy-x+y}{x^2+xy-x-y}\)
e) \(\dfrac{36\left(x-2\right)^3}{32-16x}\)
\(\dfrac{3}{x-5}-\dfrac{x+1}{x\left(x-5\right)}\)
\(\dfrac{8\left(y+2\right)}{3x^2}.\dfrac{15x^5}{4\left(y+2\right)^2}\)
\(\dfrac{8\left(y-1\right)}{3x^2-3}:\dfrac{4\left(y-1\right)^3}{x^2-2x+1}\)
Rút gọn các biểu thức sau :
A = \(2x^2\left(-3x^3+2x^2+x-1\right)+2x\left(x^2-3x+1\right)\)
B = \(2x:\dfrac{1}{2}x+x^2\)
C = \(\left[1:\left(1+x\right)+2x:\left(1-x^2\right)\right]:\left(\dfrac{1}{x}-1\right)\)
D = \(\dfrac{x^2-y^2}{x+y}.\dfrac{\left(x+y\right)^2}{x}+\dfrac{y^2}{x+y}.\dfrac{\left(x+y\right)^2}{x}\)
E = \(\dfrac{\left|x-3\right|}{x^2-9}.\left(x^2+6x+9\right)\)
F = \(\dfrac{\sqrt{x}}{\sqrt{x}-5}-\dfrac{10\sqrt{x}}{x-25}-\dfrac{5}{\sqrt{x}+5}\)
BT1: Khai triển
\(a,\left(\dfrac{x^2}{2}+y^2\right)^2\)
\(b,\left(\dfrac{4}{5}x^2-\dfrac{2}{3}y\right)^2\)
\(c,\left(2x+\dfrac{1}{2}\right)\left(2x-\dfrac{1}{2}\right)\)
Thực hiện phép tính:
a) \(\dfrac{x+2y}{xy}\div\dfrac{x^2+4xy+4y^2}{2x^2}\)
b) \(\dfrac{4x^3-xy^2}{x^2+xy+y^2}\div\dfrac{\left(2x-y\right)^3}{x^3-y^3}\)
c) \(\dfrac{x+3}{x+2}\div\dfrac{3x+9}{2x-1}\div\dfrac{4x-2}{2x+4}\)
d) \(\dfrac{x+1}{x+2}\div\left(\dfrac{2x^2}{2x-3}\times\dfrac{3x+3}{4x^3}\right)\)
Rút gọn:
a) \(\dfrac{3\left(x-y\right)\left(x-z\right)^2}{6\left(x-y\right)\left(x-z\right)}\)
b) \(\dfrac{6x^2y^2}{8xy^5}\)
c) \(\dfrac{3x\left(1-x\right)}{2\left(x-1\right)}\)
d) \(\dfrac{9-\left(x+5\right)^2}{x^2+4x+4}\)
e) \(\dfrac{x^2-2x+1}{x^2-1}\)
f) \(\dfrac{8x-4}{8x^3-1}\)
g) \(\dfrac{x^2+5x+6}{x^2+4x+4}\)
k) \(\dfrac{20x^2-45}{\left(2x+3\right)^2}\)
C/minh các đẳng thức sau:
\(a,\dfrac{2\left(x-y\right)}{3y-3x}=\dfrac{-2}{3}\)
\(b,\dfrac{x-2}{-x}=\dfrac{8-x^3}{x\left(x^2+2x+4\right)}\)
\(c,\dfrac{3x}{x+y}=\dfrac{-3x\left(x-y\right)}{y^2-x^2}\)