Question

[Kathy Nguyễn]

Rút gọn

1). \(\dfrac{2ax^2-4ax+2a}{5b-5bx^2}\)

2). \(\dfrac{x^2+4x+3}{2x+6}\)

3). \(\dfrac{4x^2-4xy}{5x^3-5x^2y}\)

4). \(\dfrac{\left(x+y\right)^2-z^2}{x+y+z}\)

Answer 1

[T.Thùy Ninh]

1) \(\dfrac{2ax^2-4ax+2a}{5b-5bx^2}\)

\(=\dfrac{2a\left(x^2-2x+1\right)}{-5b\left(x^2-1\right)}\)

\(=\dfrac{2a\left(x-1\right)^2}{-5b\left(x-1\right)\left(x+1\right)}=\dfrac{2a\left(x-1\right)}{-5b\left(x+1\right)}\)

2) \(\dfrac{x^2+4x+3}{2x+6}=\dfrac{x^2+x+3x+3}{2\left(x+3\right)}=\dfrac{x\left(x+1\right)+3\left(x+1\right)}{2\left(x+3\right)}\)\(=\dfrac{\left(x+3\right)\left(x+1\right)}{2\left(x+3\right)}=\dfrac{x+1}{2}\)

3)\(\dfrac{4x^2-4xy}{5x^3-5x^2y}=\dfrac{4x\left(x-y\right)}{5x^2\left(x-y\right)}=\dfrac{4}{5x}\)

4) \(\dfrac{\left(x+y\right)^2-z^2}{x+y+z}=\dfrac{\left(x+y+z\right)\left(x+y-z\right)}{x+y+z}=x+y-z\)Học tốt nha you<3

p/s: tớ ko bk đã rút gọn hết chưa:(