Tính
\(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
Rút gọn: \(\frac{2x^2-4xy}{x^2+4xy+4y^2}:\frac{4y^2-x^2}{x^2-4xy+4y^2}:\frac{5x^2y-10xy^2}{x^3+6x^2y+12xy^2+8y^3}\)
\(=\frac{2x\left(x-2y\right)}{\left(x+2y\right)^2}:\frac{\left(2y-x\right)\left(2y+x\right)}{\left(x-2y\right)^2}:\frac{5xy\left(x-2y\right)}{\left(x+2y\right)^3}\)
Điều kiện: \(x\ne2y;x\ne-2y;x\ne0;y\ne0\)
\(=\frac{2x\left(x-2y\right)}{\left(x+2y\right)^2}:\frac{\left(2y+x\right)}{\left(x-2y\right)}:\frac{5xy\left(x-2y\right)}{\left(x+2y\right)^3}\)
\(=\frac{2x\left(x-2y\right)}{\left(x+2y\right)^2}\times\frac{x-2y}{x+2y}\times\frac{\left(x+2y\right)^3}{5xy\left(x-2y\right)}=\frac{2\left(x-2y\right)}{5y}\)
Rút gọn: \(\frac{2x^2-4xy}{x^2+4xy+4y^2}:\frac{4y^2-x^2}{x^2-4xy+4y^2}:\frac{5x^2y-10xy^2}{x^3+6x^2y+12xy^2+8y^3}\)
\(=\dfrac{2x\left(x-2y\right)}{\left(x+2y\right)^2}\cdot\dfrac{\left(x-2y\right)^2}{-\left(x-2y\right)\left(x+2y\right)}:\dfrac{5x^2y-10xy^2}{x^3+6x^2y+12xy^3+8y^3}\)
\(=\dfrac{-2x\left(x-2y\right)^2}{\left(x+2y\right)^3}\cdot\dfrac{\left(x+2y\right)^3}{5xy\left(x-2y\right)}\)
\(=\dfrac{-2x\cdot\left(x-2y\right)}{5xy}=\dfrac{-2\left(x-2y\right)}{5y}\)
e ) \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
e) \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
\(=\frac{x}{x-2y}+\frac{x}{x+2y}-\frac{4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{x\left(x+2y\right)+x\left(x-2y\right)-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{x^2+2xy+x^2-2xy-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x^2-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x\left(x-2y\right)}{\left(x-2y\right)\left(x+2y\right)}=\frac{2x}{x+2y}\)
e ) \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
\(=\frac{x\left(x+2y\right)+x\left(x-2y\right)-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{x^2+2xy+x^2-2xy-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x^2-4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x\left(x-2y\right)}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x}{x+2y}\)
Tính: \(\frac{x^2+3xy+2y^2}{5x^2+4xy-y^2}-\frac{x^2-5xy+4y^2}{-2x^2+4xy-2y^2}\)
\(\frac{x^2+3xy+2y^2}{5x^2+4xy-y^2}-\frac{x^2-5xy+4y^2}{-2x^2+4xy-2y^2}\)
\(=\frac{x+2y}{5x-y}-\left[-\frac{x-4y}{2\left(x-y\right)}\right]\)
\(=\frac{x+2y}{5x-y}+\frac{x-4y}{2\left(x-y\right)}\)
\(=\frac{\left(x+2y\right).2\left(x-y\right)}{\left(5x-y\right).2\left(x-y\right)}+\frac{\left(x-4y\right).\left(5x-y\right)}{2\left(x-y\right).\left(5x-y\right)}\)
\(=\frac{\left(x+2y\right).2\left(x-y\right)+\left(x-4y\right).\left(5x-y\right)}{2\left(x-y\right).\left(5x-y\right)}\)
\(=\frac{7x^2-19xy}{2\left(x-y\right).\left(5x-y\right)}\)
Rút gọn:
\(\frac{2x^2-4xy}{x^2+4xy+4y^2}\): \(\frac{4y^2-x^2}{x^2-4xy+4y^2}\): \(\frac{5x^2y-10xy^2}{x^3+6x^2y+12xy^2+8y^2}\)
\(\frac{x^2+4y^2}{x^2-2y^2+xy}-\frac{4xy}{x^2-2y^2-xy}\)
lên qanda mà giải í (điện thoại di động)
các bạn khôn ghê
Thực hiện phép tính:
1,\(\frac{1-2x}{2x}+\frac{2x}{2x-1}+\frac{1}{2x-4x^2}\)
2,\(\frac{x^2+2}{x^3-1}+\frac{2}{x^2+x+1}+\frac{1}{1-x}\)
3,\(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
4,\(\frac{2x}{x^2+2xy}+\frac{y}{xy-2y^2}+\frac{4}{x^2-4y^2}\)
5,\(\left(\frac{9}{x^3-9x}+\frac{1}{x+3}\right):\left(\frac{x-3}{x^2+3x}-\frac{x}{3x+9}\right)\)
Làmmmm
1/ \(\frac{1-2x}{2x}+\frac{2x}{2x-1}+\frac{1}{2x-4x^2}\)(ĐKXĐ:x\(\ne0\), x\(\ne\frac{1}{2}\))
= \(\frac{\left(1-2x\right)\left(2x-1\right)}{2x\left(2x-1\right)}+\frac{4x^2}{\left(2x-1\right)2x}-\frac{1}{2x\left(2x-1\right)}\)
\(=\frac{2x-1-4x^2+2x+4x^2-1}{2x\left(2x-1\right)}\)
\(=\frac{4x-2}{2x\left(2x-1\right)}=\frac{2\left(2x-1\right)}{2x\left(2x-1\right)}=\frac{1}{x}\)
KL:..............
2/\(\frac{x^2+2}{x^3-1}+\frac{2}{x^2+x+1}+\frac{1}{1-x}\)(ĐKXĐ : x\(\ne1\))
\(=\frac{x^2+2}{x^3-1}+\frac{2x-2}{x^3-1}-\frac{x^2+x+1}{x^3-1}\)
\(=\frac{x^2+2+2x-2-x^2-x-1}{x^3-1}=\frac{x-1}{x^3-1}=\frac{1}{x^2+x+1}\)
Kl:....................
3/ \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)(x\(\ne\pm2y\))
= \(\frac{x^2+2xy}{x^2-4y^2}+\frac{x^2-2xy}{x^2-4y^2}-\frac{4xy}{x^2-4y^2}=\frac{2x^2-4xy}{x^2-4y^2}=\frac{2x\left(x-2y\right)}{x^2-4y^2}=\frac{2x}{x+2y}\)
Kl:................
Thực hiện phép tính
1) \(\frac{1-3x}{2x}+\frac{3x-2}{2x-1}+\frac{3x-2}{2x-4x^2}\)
2) \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
3) \(\frac{xy}{x^2-y^2}-\frac{x^2}{y^2-x^2}\)
Bạn nào bt lm, giúp mình với. Mính tick cho nè. Thanks nhiều lắm.
Tính :
a) \(x^4y-5xy^3+2xy^3-5x^4y\)
b) \(10x3y5-5xy+5x3y5+8xy\)
c) \(5xy^2\left(\frac{-3}{10}x^2y\right)+\frac{3}{4}x^3y^3\)
d) \(\frac{2}{5}x^4y^5\left(\frac{5}{4}x^2y^3\right)+\frac{5}{2}x^2y^3\left(\frac{-9}{10}x^4y^5\right)\)
e) \(-5x^2y+12xy^2+7xy-10xy+3x^2y-4xy^2\)
CÁC PN GIÚP MIK NHA ! GHI RÕ RA GIÚP ! THANK YOU VERY MUCH ! ^_<
a/=X^4*y*(1-5)+(2-5)*X*Y^3
=X^4*y*-4+-3*X*Y^3
tạm thời tớ giúp được thế thôi.để tớ còn làm nốt ba bài hình cô giao đã