Câu hỏi của Mộc Lung Hoa

Question

Quy đồng mẫu thức các phân thức:

a,$\dfrac{2x}{x^2-8x+16}$,$\dfrac{x}{3x^2-12x}$

Heo Trang · Accepted Answer

x2-8x+16=(x+4)2

3x2-12x=3x(x-4)

MTC: 3x(x-4)2

$\dfrac{2x}{x^2-8x+16}=\dfrac{2x}{\left(x-4\right)^2}=\dfrac{2x.3x}{\left(x-4\right)^2.3x}=\dfrac{6x^2}{3x\left(x-4\right)^2}$

$\dfrac{x}{3x^2-12x}=\dfrac{x}{3x\left(x-4\right)}=\dfrac{x.\left(x-4\right)}{3x\left(x-4\right)\left(x-4\right)}$Câu trả lời: x2-8x+16=(x+4)2

3x2-12x=3x(x-4)

MTC: 3x(x-4)2

$\dfrac{2x}{x^2-8x+16}=\dfrac{2x}{\left(x-4\right)^2}=\dfrac{2x.3x}{\left(x-4\right)^2.3x}=\dfrac{6x^2}{3x\left(x-4\right)^2}$

$\dfrac{x}{3x^2-12x}=\dfrac{x}{3x\left(x-4\right)}=\dfrac{x.\left(x-4\right)}{3x\left(x-4\right)\left(x-4\right)}$