Question

Answer 1

a: \(=\dfrac{y}{x}\cdot\dfrac{x}{y^2}=\dfrac{1}{y}\)

b: \(=2y^2\cdot\dfrac{x^2}{2\cdot\left(-y\right)}=-x^2y\)

c: \(=5xy\cdot\dfrac{-5x}{y^3}=-\dfrac{25x^2}{y^2}\)

Answer 2

a, \(\dfrac{y}{x}.\dfrac{x}{y^2}=\dfrac{1}{y}\)Với x > 0 ; y khác 0 

b, \(\dfrac{2y^2.x^2}{-2y}=-x^2y\)Với y < 0 

c, \(\dfrac{5xy.\left(-5x\right)}{y^3}=\dfrac{-25x^2y}{y^3}=-\dfrac{25x^2}{y^2}\)Với x < 0 ; y > 0 

d, \(\dfrac{1}{5}x^3y^3.\dfrac{4}{x^2.y^4}=\dfrac{4x^3y^3}{5x^2y^4}=\dfrac{4x}{5y}\)Với x khác 0 ; y khác 0