thực hiện phép tính (các phép tính về phân thức)
\(\frac{1}{x\left(x+y\right)}+\frac{1}{y\left(x+y\right)}+\frac{1}{x\left(x-y\right)}+\frac{1}{y\left(y-x\right)}\)
Thực hiện phép tính
\(\left(\frac{x^2-y^2}{xy}-\frac{1}{x+y}\left(\frac{x^2}{y}-\frac{y^2}{x}\right)\right):\frac{x-y}{x}\)
ĐK: \(x,y\ne0,x\ne\pm y\)
Phép tính trên bằng:
\(\left(\frac{\left(x-y\right)\left(x+y\right)}{xy}-\frac{1}{x+y}.\frac{x^3-y^3}{xy}\right):\frac{x-y}{x}\)
\(=\left(\frac{\left(x-y\right)\left(x+y\right)^2}{xy\left(x+y\right)}-\frac{\left(x-y\right)\left(x^2+xy+y^2\right)}{\left(x+y\right)xy}\right):\frac{x-y}{x}\)
\(=\left(\frac{\left(x-y\right)\left(x^2+2xy+y^2-x^2-xy-y^2\right)}{xy\left(x+y\right)}\right):\frac{x-y}{x}\)
\(=\frac{\left(x-y\right)xy}{xy\left(x+y\right)}.\frac{x}{x-y}=\frac{x}{x+y}\)
\(Cho:A=\frac{1}{\left(x+y\right)^3}\left(\frac{1}{x^4}-\frac{1}{y^4}\right)\)
\(B=\frac{2}{\left(x+y\right)^4}\left(\frac{1}{x^3}-\frac{1}{y^3}\right)\)
\(C=\frac{2}{\left(x+y\right)^5}\left(\frac{1}{x^2}-\frac{1}{y^2}\right)\)
Thực hiện phép tính : \(A+B+C\)
Thực hiện phép tính
\(\left(x^2y-\frac{1}{2}xy+y^2\right).\left(x-\frac{1}{2}y\right)-x^2y\left(x-\frac{1}{2}\right)\)
thực hiện phép tính
\(M=\frac{2}{x-y}-\frac{2}{y-z}-\frac{2}{z-x}+\frac{\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2}{\left(x-y\right)\left(y-z\right)\left(z-x\right)}\)
Thực hiện phép tính :
a) \(\left(\frac{x-y}{x+y}+\frac{x+y}{x-y}\right).\left(\frac{x^2+y^2}{2xy}+1\right).\frac{xy}{x^2+y^2}\)
b) \(\frac{1}{\left(a-b\right)\left(b-c\right)}+\frac{1}{\left(b-c\right)\left(c-a\right)}+\frac{1}{\left(c-a\right)\left(a-b\right)}\)
P/s : Giúp chauu với nhá mấy bacc kewtt :>>
\(b.=\frac{1\left(c-a\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}+\frac{1\left(a-b\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}+\frac{1\left(b-c\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\frac{1c-1a+1a-1b+1b-1c}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=-\frac{2b}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
Sr nha
Kq mik nhầm
Ko phải -2b đâu mà = 0
Oce :) Thks Moon :33
thực hiện phép tính:
a/ \(\left(x^2y^2-\frac{1}{2}xy+2y\right)\left(x-2y\right)\)
b/ \(\left(y-1\right)\left(y^2+y+1\right)+\left(\frac{1}{3}x^3y-y\right)\left(2x+y^2\right)\)
a/ (\(x^3y^2\)-\(\frac{1}{2}x^3y\) + \(2xy\) - \(2x^2y^3\) + \(xy^2\) - \(4y^2\) =
thực hiện phép tính:
\(\left(y-1\right).\left(y^2+y+1\right)+\left(\frac{1}{3}x^3y-y\right).\left(2x+y^2\right)\)
Thực hiện các phép nhân:
a) \(3x\left( {2xy - 5{x^2}y} \right)\) b) \(2{x^2}y\left( {xy - 4x{y^2} + 7y} \right)\)
c) \(\left( { - \frac{2}{3}xy^2 + 6y{z^2}} \right).\left( { - \frac{1}{2}xy} \right)\)
`a)`
`3x(2xy - 5x^2y)`
`= 3x*2xy + 3x* (-5x^2y)`
`= 6x^2y - 15x^3y`
`b)`
`2x^2y (xy - 4xy^2 + 7y)`
`= 2x^2y * xy + 2x^2y * (-4xy^2) + 2x^2y * 7y`
`= 2x^3y^2 - 8x^3y^3 + 14x^2y^2`
`c)`
`(-2/3xy^2 + 6yz^2)*(-1/2xy)`
`= (-2/3xy^2)*(-1/2xy) + 6yz^2 * (-1/2xy)`
`= 1/3x^2y^3 - 3xy^2z^2`
`a, 3x(2xy-5x^2y)`
`= 6x^2y - 15x^3y`
`b, 2x^2y(xy-4xy^2+7y)`
`= 2x^3y^2 - 8x^3y^3 + 14x^2y^2`
`c, (-2/3xy^2 + 6yz^2).(-1/2xy)`
`= 1/3x^2y^3 - 3xy^2z^2`
thực hiện tính(phân thức)
\(\frac{x^2-yz}{\left(x+y\right)\left(x+z\right)}+\frac{y^2-xz}{\left(x+y\right)\left(y+z\right)}+\frac{z^2-xy}{\left(x+z\right)\left(y+z\right)}\) (y+z nha)
\(\frac{x^2-yz}{\left(x+y\right)\left(x+z\right)}+\frac{y^2-xz}{\left(x+y\right)\left(y+z\right)}+\frac{z^2-xy}{\left(x+z\right)\left(y+z\right)}\)
\(=\frac{\left(x^2-yz\right).\left(y+z\right)}{\left(x+y\right)\left(x+z\right)\left(y+z\right)}+\frac{\left(y^2-xz\right).\left(x+z\right)}{\left(x+y\right)\left(y+z\right)\left(x+z\right)}+\frac{\left(z^2-xy\right).\left(x+y\right)}{\left(x+z\right)\left(y+z\right)\left(x+y\right)}\)
\(=\frac{x^2y-y^2z+x^2z-yz^2+y^2x-x^2z+zy^2-xz^2+z^2x-x^2y+yz^2-xy^2}{\left(x+y\right)\left(x+z\right)\left(y+z\right)}\)
\(=\frac{0}{\left(x+y\right)\left(x+z\right)\left(y+z\right)}\)
\(=0\)\(\left(\text{Đ}K:x+y,y+z,z+x\ne0\right)\)
Tham khảo nhé~