cộng trừ các phân thức
\(\frac{2x+y}{2x^2-xy}+\frac{8y}{y^2-4x^2}+\frac{2x-y}{2x^2+xy}\)
CM tổng sau :
\(\frac{2x+y}{2x^2-xy}+\frac{8y}{y^2-4x^2}+\frac{2x-y}{2x^2+xy}=\frac{2.\left(2x-y\right)}{x.\left(2x+y\right)}.\)
Thực hiện phép tính
\(\frac{2x+y}{2x^2-xy}+\frac{8y}{y^2-4x^2}+\frac{2x-y}{2x^2+xy}\)
*Cộng các phân thức sau:a) x^2/x+1 + 2x/x^2-1 + 1/1+x+1 b) 2x+y/2x^2-y + 8y/y^2-4x^2+2x-y/2x^2+xy
a) \(\dfrac{x^2}{x+1}+\dfrac{2x}{x^2-1}+\dfrac{1}{1+x+1}\) \(=\dfrac{x^2.\left(x-1\right)\left(x+2\right)}{\left(x+1\right).\left(x-1\right)\left(x+2\right)}+\dfrac{2x.\left(x+2\right)}{\left(x-1\right).\left(x+1\right).\left(x+2\right)}+\dfrac{\left(x-1\right).\left(x+1\right)}{\left(x-1\right)\left(x+1\right).\left(x+2\right)}\)
\(=\dfrac{x^2.\left(x-1\right).\left(x+2\right)+2x.\left(x+2\right)+\left(x-1\right)\left(x+1\right)}{\left(x+1\right).\left(x-1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3-2x^2+2x^2+4x+x^2-1}{\left(x-1\right)\left(x+1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3+x^2+4x-1}{\left(x^2-1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3+x^2+4x-1}{x^3+2x^2-x-2}\)
*Cộng các phân thức sau: a) x^2/x+1 + 2x/x^2-1 + 1/1+x+1 b) 2x+y/2x^2-y + 8y/y^2-4x^2+2x-y/2x^2+xy c) 1/x-y +3xy/y^3-x^3 + x-y/x^2+xy+y^2
a, \(\frac{x^2}{x+1}+\frac{2x}{x^2-1}+\frac{1}{x+1}+1\)
\(=\frac{x^2\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}-\frac{2x}{\left(x-1\right)\left(x+1\right)}+\frac{x-1}{\left(x+1\right)\left(x-1\right)}+\frac{\left(x+1\right)\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}\)
\(=\frac{x^3-x^2-2x+x-1-x^2-1}{\left(x-1\right)\left(x+1\right)}\)
\(=\frac{x^3-2x^2-x-2}{\left(x-1\right)\left(x+1\right)}\)
CM đẳng thức
\(\frac{2x+y}{2x^2-xy}\) + \(\frac{8y}{y^2-4x^2}\)+ \(\frac{2x-y}{2x^2+xy}\)= \(\frac{2\left(2x-y\right)}{x\left(2x+y\right)}\)
\(\frac{1}{x\left(x-y\right)\left(x-z\right)}\) + \(\frac{1}{y\left(y-x\right)\left(y-z\right)}\)+ \(\frac{1}{z\left(z-x\right)\left(z-y\right)}\)= \(\frac{1}{xyz}\)
Tính:\(A=\frac{2x+y}{2x^2-xy}+\frac{16x}{y^2-4x}\)\(+\frac{2x-y}{2x^2+xy}\)
kết quả này có đúng không thì mình chưa chắc bạn nhé : \(\frac{4x+16}{y^2-4x}\)
Biến đổi mỗi biểu thức sau thành phân thức
\(A=\frac{\frac{1}{x}-\frac{2}{y}}{\frac{4x^2-y^2}{x}}\)
\(B=\frac{\frac{xy-y^2}{1+xy}-xy}{\frac{x^2-xy}{1+xy}-x^2}\)
\(C=\frac{\frac{x^3-x}{x+1}+\frac{2x-2}{1+\frac{x}{2}}}{\frac{x^3-3x^2}{x-3}-\frac{2x^2+8}{x+2}}\)
thực hiện phép tính \(\frac{2x+y}{2x^2-xy}+\frac{16}{y^2-4x^2}+\frac{2-y}{2x^2+xy}\)