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Question

Rút gọn biểu thức :

$P=\dfrac{4xy}{y^2-x^2}\div\left(\dfrac{1}{y^2-x^2}+\dfrac{1}{x^2+2xy+y^2}\right)$

Adonis Baldric · Accepted Answer

$P=\dfrac{4xy}{y^2-x^2}\div\left(\dfrac{1}{\left(y-x\right).\left(y+x\right)}+\dfrac{1}{\left(x+y\right)^2}\right)$

$P=\dfrac{4xy}{y^2-x^2}\div\dfrac{x+y+y-x}{\left(y-x\right).\left(x+y\right)^2}$

$P=\dfrac{4xy}{y^2-x^2}\div\dfrac{2y}{\left(y-x\right).\left(x+y\right)^2}$

$P=\dfrac{4xy}{\left(y-x\right).\left(y+x\right)}\cdot\dfrac{\left(y-x\right).\left(x+y\right)^2}{2y}$

$P=\dfrac{2x.\left(x+y\right)}{1}=2x.\left(x+y\right)$

Xong rồi đóCâu trả lời: $P=\dfrac{4xy}{y^2-x^2}\div\left(\dfrac{1}{\left(y-x\right).\left(y+x\right)}+\dfrac{1}{\left(x+y\right)^2}\right)$

$P=\dfrac{4xy}{y^2-x^2}\div\dfrac{x+y+y-x}{\left(y-x\right).\left(x+y\right)^2}$

$P=\dfrac{4xy}{y^2-x^2}\div\dfrac{2y}{\left(y-x\right).\left(x+y\right)^2}$

$P=\dfrac{4xy}{\left(y-x\right).\left(y+x\right)}\cdot\dfrac{\left(y-x\right).\left(x+y\right)^2}{2y}$

$P=\dfrac{2x.\left(x+y\right)}{1}=2x.\left(x+y\right)$

Xong rồi đó

Bài 8: Rút gọn biểu thức chứa căn bậc hai