4xX-15=-75-x
giúp mk với
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`(x+2)/(x-2)-2/(x^2-2x)=1/x`
ĐK:`x ne 0,x ne +-2`
Nhân 2 vế với `x^2-2x ne 0` ta có pt
`x(x+2)-2=x(x-2)`
`<=>x^2+2x-2=x^2-2x`
`<=>4x=2`
`<=>x=1/2.(tm)`
Vậy `S={1/2}`
\(x:\left[\dfrac{8}{5}\cdot\left(\dfrac{2}{3}\right)^2-\dfrac{2}{5}\right]=\dfrac{15}{7}+\dfrac{6}{5}\left[\left(2\dfrac{1}{7}\right)^2-\dfrac{50}{49}\right]\)
\(\Leftrightarrow x:\left[\dfrac{32}{45}-\dfrac{18}{45}\right]=\dfrac{15}{7}+\dfrac{6}{5}\cdot\left(\dfrac{225}{49}-\dfrac{50}{49}\right)\)
\(\Leftrightarrow x:\dfrac{14}{45}=\dfrac{15}{7}+\dfrac{6}{5}\cdot\dfrac{25}{7}\)
\(\Leftrightarrow x:\dfrac{14}{45}=\dfrac{45}{7}\)
\(\Leftrightarrow x=2\)
a) \(\left|x\right|+x\)
Vì \(\left|x\right|\ge0\) nên ta có 3TH:
TH1: \(x>0\)
\(\Rightarrow\left|x\right|+x=2x\)
TH2: \(x=0\)
\(\Rightarrow\left|x\right|+x=0\)
TH3: \(x< 0\)
\(\Rightarrow\left|x\right|+x=0\)
đổi 75%=3/4.Ta có:
3/4xX+3/4xX+X=30
(3/4+3/4+1)xX=30
5/2 x X=30
X = 30:5/2
X = 12
\(75\%\times x+\frac{3}{4}\times x+x=30\)
\(\frac{3}{4}\times x+\frac{3}{4}\times x+1\times x=30\)
\(\left(\frac{3}{4}+\frac{3}{4}+1\right)\times x=30\)
\(\frac{5}{2}\times x=30\)
\(x=30\div\frac{5}{2}\)
\(x=12\)
= 75% x X + 3/4 x X + X = 30
= X x (3/4 + 3/4 + 1) = 30
= X x 10/4 = 30
= X = 30 : 10/4
X = 12
0,75 x X + 0,75 x X + X = 30
X x ( 0,75 + 0,75 + 1 ) = 30
X x 2,5 = 30
X = 30 : 2,5
X = 12
75%xX+3/4xX+X=30
<=>3/4xX+3/4xX+X=30
<=>10/4xX=30
<=>10xX=120
<=>X=120/10=12
Vậy X=12
\(75\%\cdot x+\frac{3}{4}\cdot x+x=30\)
\(x\cdot\left(\frac{3}{4}+\frac{3}{4}+1\right)=30\)
\(x\cdot\frac{5}{2}=30\)
\(x=30\cdot\frac{2}{5}\)
\(x=12\)
4x - 15 = -75 - x
4x + x = -75 + 15
5x = -60
x = -60/5
x = -12
\(4\times x-15=-75-x\)
\(\Leftrightarrow4x-15+75=-x\)
\(\Leftrightarrow4x+60=-x\)
\(\Leftrightarrow60=-x-4x\)
\(\Leftrightarrow60=-5x\)
\(\Leftrightarrow x=-12\)
Vậy \(x=-12\)