Bài 4: Rút gọn các phân thức sau:
a,\(\dfrac{-12acx^2}{26a^2c^2x}\)
b,\(\dfrac{38m^3n^4p^2}{57m^4n^4p}\)
c,\(\dfrac{x\left(5-x\right)}{x^2\left(x-5\right)}\)
d,\(\dfrac{2x-6x}{x^2-9y^2}\)
e, \(\dfrac{x^2-2x}{x^3-4x}\)
g, \(\dfrac{xy^3-yx^3}{x^2+xy}\)
h, \(\dfrac{a^2x^3-a^2}{ax^2+ax+a}\)
i, \(\dfrac{x^2-3x}{9-x^2}\)
l, \(\dfrac{x^2-x-xy+y}{xy-x-y^2+y}\)
m, \(\dfrac{\left(x-y\right)\left(2x+30\right)}{y^2-yx}\)
n, \(\dfrac{4x^2+12x+9 }{2x^2-x-6}\)
q, \(\dfrac{x^2+8x-9}{x^2+7x-8}\)
r, \(\dfrac{x^2+y^2-z^2+2xy}{x^2-y^2+z^2+2zx}\)
t,\(\dfrac{x^4+x^3x-1}{x^4+x^3}\)
Bài 5: Rút gọn các phân thức rồi tính giá trị
a, A = \(\dfrac{x^4-2x^3}{2x^2-x^3}\)với x = -\(\dfrac{1}{2}\)
b, B = \(\dfrac{x^2-6x+9}{x^2-8x+15}\)với x= -2
c, C = \(\dfrac{4x+2}{4x^2-1}\)với x= -3
