`***`Lời giải`***`
f)
`\frac{x^2-36}{2x+10}.\frac{3}{6-x}`
`=\frac{(x-6)(x+6)}{2(x+5)}.\frac{-3}{x-6}`
`=\frac{-3(x-6)(x+6)}{2(x+5)(x-6)}`
`=\frac{-3(x+6)}{2(x+5)}`
g)
`\frac{x^2-9y^2}{x^2y^2}.\frac{3xy}{2x-6y}`
`=\frac{(x-3y)(x+3y)}{x^2y^2}.\frac{3xy}{2(x-3y)}`
`=\frac{3xy(x-3y)(x+3y)}{2(x-3y)x^2y^2}`
`=\frac{3(x+3y)}{2xy}`
h)
`\frac{3x^2-3y^2}{5xy}.\frac{15x^2y}{2y-2x} `
`=\frac{3(x^2-y^2)}{5xy}.\frac{15x^2y}{2(y-x)} `
`=\frac{3(x+y)(x-y)}{5xy}.\frac{-15x^2y}{2(x-y)} `
`=\frac{-45x^2y(x+y)(x-y)}{10(x-y)xy} `
`=\frac{-9x(x+y)}{2} `
