4X-1+3=67
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4 \(\times\) (\(x-1\))3 - 1 = 3
4 \(\times\) (\(x\) - 1)3 = 3 + 1
4 \(\times\) (\(x-1\))3 = 4
(\(x-1\))3 = 4:4
(\(x-1\))3 = 1
\(x-1=1\)
\(x\) = 1 + 1
\(x\) = 2
\(\sqrt{x-2}=3\left(x\ge2\right)\\ \Leftrightarrow x-2=9\Leftrightarrow x=11\left(tm\right)\\ \sqrt{4x^2}+4x+1=3\Leftrightarrow\left|2x\right|=2-4x\\ \Leftrightarrow\left[{}\begin{matrix}2x=2-4x\left(x\ge0\right)\\2x=4x-2\left(x< 0\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\left(tm\right)\\x=1\left(ktm\right)\end{matrix}\right.\Leftrightarrow x=\dfrac{1}{3}\)
a: Ta có: \(\left(3x-1\right)^2-\left(3x+4\right)\left(3x-4\right)=32\)
\(\Leftrightarrow9x^2-6x+1-9x^2+16=32\)
\(\Leftrightarrow-6x=15\)
hay \(x=-\dfrac{5}{2}\)
b: Ta có: \(\left(4x+3\right)^2-\left(4x-1\right)\left(4x+1\right)=-14\)
\(\Leftrightarrow16x^2+24x+9-16x^2+1=-14\)
\(\Leftrightarrow24x=-24\)
hay x=-1
a) \((4x-1)^3-(4x-3)(16x^2+3)\)
\(=(4x)^3-3.(4x)^2.1+3.4x.1^2-1^3-(4x-3) (16x^2+3)\)
\(=64x^3-48x^2+12x-1-64x^3-12x-48x^2-9\)
\(=9\)
\(a,\left(4x-1\right)^3-\left(4x-3\right)\left(16x^2+3\right)\)
\(=64x^3-48x^2+12x-1-64x^3-4x+48x^2+9\)\(=12x+8\)
\(b,2\left(x^3+y^3\right)-3\left(x^2+y^2\right)\)
\(=2\left(x+y\right)\left(x^2-xy+y^2\right)-3\left[\left(x+y\right)^2-2xy\right]\)\(=2x^2-2xy+2y^2+6xy\) ( vì x + y =1 )
\(=2x^2+4xy+2y^2\)
\(=2\left(x^2+2xy+y^2\right)=2\left(x+y\right)^2=2\)
a. \(4x\left(3x-2\right)-3x\left(4x+1\right)\)
\(=12x^2-8x-12x^2-3x\)
\(=-11x\) \(\left(1\right)\)
Thay \(x=-2\) vào \(\left(1\right)\) ta được :
\(-11.\left(-2\right)=22\)
b. \(\left(x+3\right)\left(x-3\right)-\left(x-1\right)^2\)
\(=\left(x^2-9\right)-\left(x^2-2x+1\right)\)
\(=x^2-9-x^2+2x-1\)
\(=2x-10\) \(\left(2\right)\)
Thay \(x=6\) vào \(\left(2\right)\) ta được :
\(2.6-10=2\)
a, \(A=\left(\frac{1-4x^2}{x^2+4x}\right)-\frac{3-4x}{3x}\)
\(=\left(\frac{3x\left(1-4x^2\right)}{3x\left(x^2+4x\right)}\right)-\frac{\left(3-4x\right)\left(x^2+4x\right)}{3x\left(x^2+4x\right)}\)
\(=\frac{3x-12x^3-3x^2-12x+4x^3-16x^2}{3x^2\left(x+4\right)}=\frac{3x-8x^3-19x^2}{3x^2\left(x+4\right)}\)
\(=\frac{3x^2\left(\frac{1}{x}-\frac{8x}{3}-\frac{19}{3}\right)}{3x^2\left(x+4\right)}=\frac{\frac{1}{x}-\frac{8x}{3}-\frac{19}{3}}{x+4}\)
Kiểm tra lại đề hộ mình nhá
ĐKXĐ của A là : \(\hept{\begin{cases}x^2+4x\ne0\\3x\ne0\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x\times\left(x+4\right)\ne0\\x\ne\frac{0}{3}=0\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x\ne0\\x+4\ne\\x\ne0\end{cases}0}\)
\(\Leftrightarrow\hept{\begin{cases}x\ne0\\x\ne\\x\ne0\end{cases}-4}\)
Với \(x=\frac{1}{2}\left(TMĐKXĐ\right)\)Thì
A = \(\frac{1-4\times\left(\frac{1}{2}\right)^2}{\left(\frac{1}{2}\right)^2+4\times\frac{1}{2}}-\frac{3-4\times\frac{1}{2}}{3\times\frac{1}{2}}\)
\(=\frac{1-4\times\frac{1}{4}}{\frac{1}{4}+2}-\frac{3-2}{\frac{3}{2}}\)
\(=\frac{1-1}{\frac{1}{4}+\frac{8}{4}}-\frac{1}{\frac{3}{2}}\)
\(=\frac{0}{\frac{9}{4}}-1\div\frac{3}{2}\)
\(=0-1\times\frac{2}{3}\)
\(=0-\frac{2}{3}\)
\(=-\frac{2}{3}\)
Vậy tại \(x=\frac{1}{2}\)thì A có giá trị là \(-\frac{2}{3}\)
4x-1=67-3
4x=64
4x=416
x=416+1
nha kq tự tính