Question

[bella nguyen]

Câu 1 : thực hiện phép tính

a, 5x + y^2 / x^2y - 5y - x^2/ xy^2

b, x + 9 /x^2 - 9 - 3/ x^2 + 3x

c, 18/ x-3(x^2 - 9) - 3/ x^2 - 6x + 9 -x^2 / x^2 + 3x

Help meeeeee

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(\dfrac{5x+y^2}{x^2y}-\dfrac{5y-x^2}{xy^2}\)

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

\(=\dfrac{5xy+y^3-5xy+x^3}{x^2y^2}=\dfrac{x^3+y^3}{x^2y^2}\)

b: \(\dfrac{x+9}{\left(x-3\right)\left(x+3\right)}-\dfrac{3}{x\left(x+3\right)}\)

\(=\dfrac{x^2+9x-3x+9}{x\left(x-3\right)\left(x+3\right)}=\dfrac{\left(x+3\right)^2}{x\left(x-3\right)\left(x+3\right)}=\dfrac{x+3}{x^2-3x}\)