a/ \(\dfrac{3x^2y+5}{15x^3y^4}+\dfrac{3x^2y-5}{15x^3y^4}=\dfrac{3x^2y+5+3x^2y-5}{15x^3y^4}=\dfrac{6x^2y}{15x^3y^4}=\dfrac{2}{5xy^3}\)
b/ \(\dfrac{2x^2-x}{x^2+x+1}+\dfrac{x^3-2x^2+x+1}{x^2+x+1}=\dfrac{2x^2-x+x^3-2x^2+x+1}{x^2+x+1}=\dfrac{x^3+1}{x^2+x+1}\)
Cộng các phân thức khác mẫu thức :
a) \(\dfrac{5}{6x^2y}+\dfrac{7}{12xy^2}+\dfrac{11}{18xy}\)
b) \(\dfrac{4x+2}{15x^3y}+\dfrac{5y-3}{9x^2y}+\dfrac{x+1}{5xy^3}\)
c) \(\dfrac{3}{2x}+\dfrac{3x-3}{2x-1}+\dfrac{2x^2+1}{4x^2-2x}\)
d) \(\dfrac{x^3+2x}{x^3+1}+\dfrac{2x}{x^2-x+1}+\dfrac{1}{x+1}\)
Cộng các phân thức cùng mẫu thức :
a) \(\dfrac{1-2x}{6x^3y}+\dfrac{3+2y}{6x^3y}+\dfrac{2y-4}{6x^3y}\)
b) \(\dfrac{x^2-2}{x\left(x-1\right)^2}+\dfrac{2-x}{x\left(x-1\right)^2}\)
c) \(\dfrac{3x+1}{x^2-3x+1}+\dfrac{x^6-6x}{x^2-3x+1}\)
d) \(\dfrac{x^2+38x+4}{2x^2+17x+1}+\dfrac{3x^2-4x-2}{2x^2+17x+1}\)
Làm tính cộng các phân thức :
a) \(\dfrac{11x+13}{3x-3}+\dfrac{15x+17}{4-4x}\)
b) \(\dfrac{2x+1}{2x^2-x}+\dfrac{32x^2}{1-4x^2}+\dfrac{1-2x}{2x^2+x}\)
c) \(\dfrac{1}{x^2+x+1}+\dfrac{1}{x^2-x}+\dfrac{2x}{1-x^3}\)
d) \(\dfrac{x^4}{1-x}+x^3+x^2+x+1\)
1, Thực hiện phép tính:
a, \(\dfrac{1-3x}{2}+\dfrac{x+3}{2}\)
b, \(\dfrac{2\left(x+y\right)\left(x-y\right)}{x}-\dfrac{-2y^2}{x}\)
c, \(\dfrac{3x+1}{x+y}-\dfrac{2x-3}{x+y}\)
d, \(\dfrac{xy}{2x-y}-\dfrac{x^2-1}{y-2x}\)
e, \(\dfrac{4x-1}{3x^2y}-\dfrac{7x-1}{3x^2y}\)
2, Thực hiện phép tính:
a, \(\dfrac{1}{x}.\dfrac{6x}{y}\)
b, \(\dfrac{2x^2}{y}.3xy^2\)
c, \(\dfrac{15x}{7y^3}.\dfrac{2y^2}{x^2}\)
d, \(\dfrac{2x^2}{x-y}.\dfrac{y}{5x^3}\)
e, \(\dfrac{5x+10}{4x-8}.\dfrac{4-2x}{x+2}\)
f, \(\dfrac{x^2-36}{2x+10}.\dfrac{3}{6-x}\)
Làm tính cộng các phân thức sau :
a) \(\dfrac{5}{2x^2y}+\dfrac{3}{5xy^2}+\dfrac{x}{y^3}\)
b) \(\dfrac{x+1}{2x+6}+\dfrac{2x+3}{x\left(x+3\right)}\)
c) \(\dfrac{3x+5}{x^2-5x}+\dfrac{25-x}{25-5x}\)
d) \(x^2+\dfrac{x^4+1}{1-x^2}+1\)
e) \(\dfrac{4x^2-3x+17}{x^3-1}+\dfrac{2x-1}{x^2+x+1}+\dfrac{6}{1-x}\)
Dùng quy tắc đổi dấu để tìm mẫu thức chung rồi thực hiện phép cộng :
a) \(\dfrac{4}{x+2}+\dfrac{2}{x-2}+\dfrac{5x-6}{4-x^2}\)
b) \(\dfrac{1-3x}{2x}+\dfrac{3x-2}{2x-1}+\dfrac{3x-2}{2x-4x^2}\)
c) \(\dfrac{1}{x^2+6x+9}+\dfrac{1}{6x-x^2-9}+\dfrac{x}{x^2-9}\)
d) \(\dfrac{x^2+2}{x^3-1}+\dfrac{2}{x^2+x+1}+\dfrac{1}{1-x}\)
e) \(\dfrac{x}{x-2y}+\dfrac{x}{x+2y}+\dfrac{4xy}{4y^2-x^2}\)
Thực hiện các phép tính sau :
a) \(\dfrac{3x-5}{7}+\dfrac{4x+5}{7}\)
b) \(\dfrac{5xy-4y}{2x^2y^3}+\dfrac{3xy+4y}{2x^2y^3}\)
c) \(\dfrac{x+1}{x-5}+\dfrac{x-18}{x-5}+\dfrac{x+2}{x-5}\)
Thực hiện phép cộng các phân thức sau:
\(\dfrac{5x-1}{3x^2y}+\dfrac{x+1}{3x^2y}\\ \dfrac{7}{12xy^2}+\dfrac{11}{18x^3y}\\ \dfrac{x}{x+2}+\dfrac{7x-16}{\left(x+2\right)\left(4x-7\right)}\)
tính:
a, \(\dfrac{1}{1-x}+\dfrac{1}{1+x}+\dfrac{2}{1+x^2}+\dfrac{4}{1+x^2}+\dfrac{4}{1+x^4}+\dfrac{8}{1+x^8}+\dfrac{16}{1+x^{16}}\)
b, 2y - \(\dfrac{6xy+2y}{3x+2y}+\dfrac{2y-9x^2}{3x+2y}\)
