1)
a) \(x^2\)+6x +9 ; b) 10x - 25 - \(x^2\)
c) 8\(x^3\) -\(\dfrac{1}{8}\) ; d) \(\dfrac{1}{25}\)\(x^2\) - 64\(y^2\)
LN
Những câu hỏi liên quan
cho a=căn(x^2-6x+9)-căn(x^2-6x+9)
a)rút gọn
b)tìm giá trị x để a=1
Tìm x
a) ( x2- 6x+ 9)2 - 15 (x2- 6x + 10) = 1
b) (x2- 9) = 12x + 1
a,a) ( x2- 6x+ 9)2 - 15 (x2- 6x + 10) = 1
Đặt (x2-6x+9)=a\(\left(a\ge0\right)\)Ta có:
a2-15(a+1)=1
<=> a2-15a-15-1=0
<=>a2-15a-16=0
<=>a2-16a+a-16=0
<=>a(a-16)+(a-16)=0
<=>(a-16)(a+1)=0\(\Rightarrow\orbr{\begin{cases}a-16=0\\a+1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}a=16\\a=-1\end{cases}}}\)
Vậy...
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Giải pt
a)căn x^2-4x+4x+3
a)căn 9x^2+12x+44x
a)căn x^2-8x+164-x
a)căn 9x^2-6x+1-5x2
a)căn 25-10x+x^2-2x1
a)căn 25x^2-30x+9x-1
a)căn x^2-6x+9-x-50
a)2x^2-căn 9x^2-6x+1-5
b)căn x+5căn 2x
b)căn 2x-1căn x-1
b)căn 2x+5căn 1-x
b)căn x^2-xcăn 3-x
b)căn 3x+1căn 4x-3
b)căn x^2-x3x-5
b)căn 2x^2-3căn 4x-3
b)căn x^2-x-6căn x-3
Giúp mình với ạ
Đọc tiếp
Giải pt
a)căn x^2-4x+4=x+3
a)căn 9x^2+12x+4=4x
a)căn x^2-8x+16=4-x
a)căn 9x^2-6x+1-5x=2
a)căn 25-10x+x^2-2x=1
a)căn 25x^2-30x+9=x-1
a)căn x^2-6x+9-x-5=0
a)2x^2-căn 9x^2-6x+1=-5
b)căn x+5=căn 2x
b)căn 2x-1=căn x-1
b)căn 2x+5=căn 1-x
b)căn x^2-x=căn 3-x
b)căn 3x+1=căn 4x-3
b)căn x^2-x=3x-5
b)căn 2x^2-3=căn 4x-3
b)căn x^2-x-6=căn x-3
Giúp mình với ạ
a) \(\sqrt[]{x^2-4x+4}=x+3\)
\(\Leftrightarrow\sqrt[]{\left(x-2\right)^2}=x+3\)
\(\Leftrightarrow\left|x-2\right|=x+3\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=x+3\\x-2=-\left(x+3\right)\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}0x=5\left(loại\right)\\x-2=-x-3\end{matrix}\right.\)
\(\Leftrightarrow2x=-1\Leftrightarrow x=-\dfrac{1}{2}\)
b) \(2x^2-\sqrt[]{9x^2-6x+1}=5\)
\(\Leftrightarrow2x^2-\sqrt[]{\left(3x-1\right)^2}=5\)
\(\Leftrightarrow2x^2-\left|3x-1\right|=5\)
\(\Leftrightarrow\left|3x-1\right|=2x^2-5\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-1=2x^2-5\\3x-1=-2x^2+5\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}2x^2-3x-4=0\left(1\right)\\2x^2+3x-6=0\left(2\right)\end{matrix}\right.\)
Giải pt (1)
\(\Delta=9+32=41>0\)
Pt \(\left(1\right)\) \(\Leftrightarrow x=\dfrac{3\pm\sqrt[]{41}}{4}\)
Giải pt (2)
\(\Delta=9+48=57>0\)
Pt \(\left(2\right)\) \(\Leftrightarrow x=\dfrac{-3\pm\sqrt[]{57}}{4}\)
Vậy nghiệm pt là \(\left[{}\begin{matrix}x=\dfrac{3\pm\sqrt[]{41}}{4}\\x=\dfrac{-3\pm\sqrt[]{57}}{4}\end{matrix}\right.\)
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Rút gọn M và A sau đây :
M= \(\left(\dfrac{x}{x+3}+\dfrac{3-x}{x+3}.\dfrac{x^2+3x+9}{x^2-9}\right)\)
A= \(\left(\dfrac{3x}{1-3x}-\dfrac{2x}{3x+1}\right):\dfrac{6x^2+10x}{1-6x+9x^2}\)
a)4/x+2+2/x-2+5x-6/4-x2 ; b)1-3x/2x+3x-2/2x-1+3x-2/2x-4x2 ; c)1/x2+6x+9+1/6x-x2-9+x/x2-9
Thực hiện phép tính : 1/x^2+6x+9 + 1/6x-x^2-9 + x/x^2-9
Thực hiện phép tính : 1/x^2+6x+9 + 1/6x-x^2-9 + x/x^2-9
Cứu với mn ơi huhu !!
Cho A= \(\sqrt{x^2-6x+9}-\sqrt{x^2+6x+9}\)
a, Tính A
b, tìm x khi A =1
a/ \(A=\sqrt{\left(x-3\right)^2}-\sqrt{\left(x+3\right)^2}=\left|x-3\right|-x-3\)
b/ \(A=1\Leftrightarrow\left|x-3\right|-x-3=1\)
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a)4x+3/6x-4+5x-9/6x-4
b) 2/x-1+3/x+1-4x-2/x2-1
a) \(\frac{4x+3}{6x-4}+\frac{5x-9}{6x-4}\)
\(=\frac{4x+3+5x-9}{2\left(3x-2\right)}=\frac{9x-6}{2\left(3x-2\right)}\)
\(=\frac{3\left(3x-2\right)}{2\left(3x-2\right)}=\frac{3}{2}\)
b) \(\frac{2}{x-1}+\frac{3}{x+1}-\frac{4x-2}{x^2-1}\)
\(=\frac{2\left(x+1\right)+3\left(x-1\right)-4x+2}{\left(x-1\right)\left(x+1\right)}\)
\(=\frac{x+1}{\left(x-1\right)\left(x+1\right)}=\frac{1}{x-1}\)
a) \(\frac{4x+3}{6x-4}+\frac{5x-9}{6x-4}\)
\(=\frac{4x+3+5x-9}{6x-4}\)
\(=\frac{9x-6}{6x-4}\)
\(=\frac{3.\left(3x-2\right)}{2.\left(3x-2\right)}\)
\(=\frac{3}{2}.\)
b) \(\frac{2}{x-1}+\frac{3}{x+1}-\frac{4x-2}{x^2-1}\)
\(=\frac{2}{x-1}+\frac{3}{x+1}-\frac{4x-2}{\left(x-1\right).\left(x+1\right)}\)
\(=\frac{2.\left(x+1\right)}{\left(x-1\right).\left(x+1\right)}+\frac{3.\left(x-1\right)}{\left(x-1\right).\left(x+1\right)}-\frac{4x-2}{\left(x-1\right).\left(x+1\right)}\)
\(=\frac{2x+2}{\left(x-1\right).\left(x+1\right)}+\frac{3x-3}{\left(x-1\right).\left(x+1\right)}+\frac{-\left(4x-2\right)}{\left(x-1\right).\left(x+1\right)}\)
\(=\frac{2x+2+3x-3-4x+2}{\left(x-1\right).\left(x+1\right)}\)
\(=\frac{x+1}{\left(x-1\right).\left(x+1\right)}\)
\(=\frac{1}{x-1}.\)
Chúc bạn học tốt!
\(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
\(\frac{1}{x^2+6x+9}+\frac{1}{6x-x^2-9}+\frac{x}{x^2-9}\)
\(=\frac{1}{\left(x+3\right)^2}+-\frac{1}{\left(x-3\right)^2}+\frac{x}{\left(x+3\right)\left(x-3\right)}\)
\(=\frac{\left(x-3\right)^2-\left(x+3\right)^2+x\left(x+3\right)\left(x-3\right)}{\left(x+3\right)^2\left(x-3\right)^2}\)
\(=\frac{x^2-6x+9-x^2-6x-9+x^3-9x}{\left(x+3\right)^2\left(x-3\right)^2}\)
\(=\frac{x^3-21x}{\left(x+3\right)^2\left(x-3\right)^2}\)
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