bài 1. rút gọn phân thức sau :
a, \(\dfrac{15xy}{10x^2y}\)
b, \(\dfrac{4\left(2-x\right)}{6x\left(x-2\right)}\)
c, \(\dfrac{12x^3\left(x-4\right)^2}{8x^2\left(4-x\right)}\)
d, \(\dfrac{6x\left(x+5\right)^3}{2x^2\left(x+5\right)}\)
bài 2. rút gọn phân thức sau :
a, \(\dfrac{15\left(x-3\right)^3}{9-3x}\)
b, \(\dfrac{4\left(5x-1\right)^3}{2-10x}\)
c,\(\dfrac{9x^2y}{-15x^3y}\)
d, \(\dfrac{-15x\left(x-y\right)^2}{6x^2\left(x-y\right)^3}\)
bài 3. rút gọn phân thức sau :
a, \(\dfrac{5x^2+10x+5}{11x+11}\)
b, \(\dfrac{18x+6x^2+2x^3}{x^3-27}\)
c, \(\dfrac{12x^2+12x+3}{4x^2-1}\)
bài 4 : rút gọ phân thức đại số
A= \(\dfrac{12xy^2}{-9x^3y}\)
B=\(\dfrac{35xy\left(x-4\right)^2}{28x^2\left(4-x\right)}\)
C= \(\dfrac{6x+18y}{x^2-9y^2}\)
Bài 1:
a) \(\dfrac{15xy}{10x^2y}\)
= \(\dfrac{3.5xy}{2.5xyx}\)
= \(\dfrac{3}{2x}\)
d) \(\dfrac{6x\left(x+5\right)^3}{2x^2\left(x+5\right)}\)
= \(\dfrac{3.2x\left(x+5\right)\left(x+5\right)^2}{x.2x\left(x+5\right)}\)
= \(\dfrac{3\left(x+5\right)^2}{x}\)
Bài 2:
c) \(\dfrac{9x^2y}{-15x^3y}\)
= -\(\dfrac{3.3x^2y}{5.3x^2yx}\)
= -\(\dfrac{3}{5x}\)
d) \(\dfrac{-15x\left(x-y\right)^2}{6x^2\left(x-y\right)^3}\)
= \(\dfrac{5.3x\left(x-y\right)^2}{2x.3x\left(x-y\right)^2\left(x-y\right)}\)
= \(\dfrac{5}{2x\left(x-y\right)}\)
= \(\dfrac{5}{2x^2-2xy}\)
Bài 4:
1: \(A=\dfrac{12xy^2}{-9x^3y}=\dfrac{-4y}{3x^2}\)
2: \(B=\dfrac{-35xy\cdot\left(x-4\right)^2}{28x^2\left(x-4\right)}=\dfrac{-5y\left(x-4\right)}{7x}\)
3: \(C=\dfrac{6\left(x+3y\right)}{\left(x+3y\right)\left(x-3y\right)}=\dfrac{6}{x-3y}\)
