c ) \(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
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C=\(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
\(C=\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}.\)
\(C=\frac{1}{\left(x+3\right)^2}+\frac{-1}{-\left(6x-x^2-9\right)}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)
\(C=\frac{1}{\left(x+3\right)^2}+\frac{-1}{-6x+x^2+9}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)
\(C=\frac{x-3}{\left(x+3\right)\left(x-3\right)}+\frac{-\left(x+3\right)}{\left(x+3\right)\left(x-3\right)}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)
\(C=\frac{x-3.-x-3.x}{\left(x+3\right).\left(x-3\right)}=\frac{-6x}{\left(x+3\right)\left(x-3\right)}=\frac{-6x}{\left(x^2-9\right)}\)
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\(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
\(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
\(=\frac{1}{\left(x+3\right)^2}+-\frac{1}{\left(x-3\right)^2}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)
\(=\frac{\left(x-3\right)^2-\left(x+3\right)^2+x\left(x+3\right)\left(x-3\right)}{\left(x+3\right)^2\left(x-3\right)^2}\)
\(=\frac{x^2-6x+9-x^2-6x-9+x^3-9x}{\left(x+3\right)^2\left(x-3\right)^2}\)
\(=\frac{x^3-21x}{\left(x+3\right)^2\left(x-3\right)^2}\)
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Thực hiện phép tính:
\(\frac{1}{x^2+6x+9}\)+\(\frac{1}{6x-9x^2-9}+\frac{x}{x^2-9}\)
Thực hiện phép tình:
\(\left[\frac{1}{x^2+6x+9}-\frac{1}{x^2-6x+9}\right]:\left[\frac{1}{x+3}+\frac{1}{x-3}\right]\)
Rút gọn: \(\left(\frac{1}{x^2+6x+9}-\frac{1}{x^2-6x+9}\right)\left(\frac{1}{x+3}+\frac{1}{x-3}\right)\)
1/(x^2+6x+9)-1/(x^2-6x+9)=(x-3)/(x-3)(x+3)-(x+3)/(x-3)(x+3)= -6/(x-3)(x+3)
1/(x+3)+1/(x-3)=
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sai rồi bấm lộn thôi mà
I am sorry
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\(\frac{3x}{5x+5y}-\frac{x}{10x-10y}\\ \left(\frac{3x}{1-3n}+\frac{2n}{3x+1}\right):\left(\frac{6x^2+10x}{1-6x+9x^2}\right)\\ \left(\frac{9}{x^3-9n}+\frac{1}{x+3}\right):\left(\frac{x}{3n+9}\right)\)
\(\frac{3x}{5x+5y}-\frac{x}{10x-10y}\)
= \(\frac{3x\left(x-y\right)}{5.2.\left(x+y\right)\left(x-y\right)}-\frac{x\left(x+y\right)}{10\left(x^2-y^2\right)}\)
= \(\frac{3x^2-3xy-x^2-xy}{10\left(x^2-y^2\right)}\)
= \(\frac{3x\left(x-y\right)}{10\left(x^2-y^2\right)}\)
= \(\frac{3x}{10\left(x+y\right)}\)
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1. Thực hiện phép tính:
a) \(\frac{1-3x}{2x}+\frac{3x-2}{2x-1}+\frac{3x-2}{2x-4}\)
b) \(\frac{1}{x^2+6x+y}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
c) \(\frac{x^2+2}{x^3-1}+\frac{2}{x^2+x+1}+\frac{1}{1-x}\)
d) \(\frac{x}{x-2y}+\frac{x}{x+2y}+\frac{4xy}{4y^2-x^2}\)
a)có khả năng sai đề bài
b)Liệu có sai đề bài không
c)\(=\frac{x^2+2}{\left(x-1\right)\left(x^2+x+1\right)}+\frac{2\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}+\frac{-\left(x^2+x+1\right)}{\left(x-1\right)\left(x^2+x+1\right)}\)(phân số cuối có âm vì (1-x)=-(x-1)
\(=\frac{x^2+2+2x-2-x^2-x-1}{\left(x-1\right)\left(x^2+x+1\right)}\)(Hơi tắt)
\(=\frac{x-1}{\left(x-1\right)\left(x^2+x+1\right)}=\frac{1}{x^2+x+1}\)
d)\(=\frac{x\left(x+2y\right)}{\left(x-2y\right)\left(x+2y\right)}+\frac{x\left(x-2y\right)}{\left(x-2y\right)\left(x+2y\right)}+\frac{4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{x^2+2xy+x^2-2xy+4xy}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\frac{2x^2+4xy}{\left(x-2y\right)\left(x+2y\right)}=\frac{2x\left(x+2y\right)}{\left(x-2y\right)\left(x+2y\right)}=\frac{2x}{x-2y}\)
BÀI 5 : CHO
E=\(\frac{x^2+6x+9}{x^3+3x^2-27x+27}\). \(\left(\frac{x^2+6x+9}{x^3+3x^2-27x+27}+\frac{2}{3x}:\left(\frac{1}{x}+\frac{1}{3}\right)^2\right)\)
F=\(\frac{3+x}{3-x}\) .\(\frac{x^2-6x+9}{9x^2}\).\(\left(\frac{3}{3-x}-\frac{9}{27+x^3}.\frac{x^2-3x+9}{3-x}\right)\)
a, RÚT GỌN E VÀ F
\(a)\frac{1}{x+3}+\frac{x}{x^2-6x+9}\)
\(b)\frac{2x}{x^2-9}-\frac{x-1}{x+3}\)
\(c)\frac{2x+1}{x-2}.\frac{2-x}{2x+1}\)
Tính
a) \(\frac{1}{x+3}+\frac{x}{x^2-6x+9}\left(x\ne\pm3\right)\)
\(=\frac{1}{x+3}+\frac{x}{\left(x-3\right)^2}=\frac{\left(x-3\right)^2}{\left(x+3\right)\left(x-3\right)^2}+\frac{x^2+3x}{\left(x+3\right)\left(x-3\right)^2}\)
\(=\frac{x^2-6x+9-x^2+3x}{\left(x-3\right)^2\left(x+3\right)}=\frac{-3x+9}{\left(x-3\right)^2\left(x+3\right)}=\frac{-3\left(x-3\right)}{\left(x-3\right)^2\left(x+3\right)}=\frac{-3}{\left(x-3\right)\left(x+3\right)}\)
anhdun_•Ŧ๏áйツɦọς• giải a r nha , tớ giải b+c cho
\(b,\frac{2x}{x^2-9}-\frac{x-1}{x+3}\)
\(\frac{2x}{x^2-3^2}-\frac{x-1}{x+3}\)
\(\frac{2x}{\left(x+3\right)\left(x-3\right)}-\frac{x-1}{x+3}\)
\(\frac{2x-\left(x-1\right)\left(x-3\right)}{\left(x+3\right)\left(x-3\right)}\)
\(\frac{2x-x^2+3x+x-3}{\left(x+3\right)\left(x-3\right)}\)
\(\frac{\left(2x+3x+x\right)-x^2-3}{\left(x+3\right)\left(x-3\right)}\)
\(\frac{6x-x^2-3}{\left(x+3\right)\left(x-3\right)}\)
\(c,\frac{2x+1}{x-2}.\frac{2-x}{2x+1}\)
\(\frac{1}{x-2}\left(2-x\right)\)
\(\frac{2-x}{x-2}\)
\(-\frac{-2+x}{x-2}=-1\)