Tìm x :
a)\(\dfrac{x-1}{x=5}=\dfrac{6}{7}\)
b)\(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+4}\)
a) \(\dfrac{x-1}{x+5}=\dfrac{6}{7}\Rightarrow7\left(x-1\right)=6\left(x+5\right)\)
\(\Rightarrow7x-7=6x+30\Rightarrow7x-6x=30+7\)
\(\Rightarrow x=37\)
b) \(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+4}\)
\(\Rightarrow\left(x-1\right)^{x+2}-\left(x-1\right)^{x+4}=0\)
\(\Rightarrow\left(x-1\right)^{x+2}\left[1-\left(x-1\right)^2\right]=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(x-1\right)^{x+2}=0\\1-\left(x-1\right)^2=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x-1=0\\\left(x-1\right)^2=1\Rightarrow\left[{}\begin{matrix}x-1=1\\x-1=-1\end{matrix}\right.\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=1\\x=2\\x=0\end{matrix}\right.\)
Vậy=...
BT3: Tìm các cặp số (x,y) thỏa mãn : \(\left(x-y\right)^{2016}+\text{|}x^2-2y\text{|}=0\)
Tìm x , biết
a) \(\left|x-4\right|=6\)
b) \(\dfrac{x}{5}=\dfrac{9}{7}\)
c) \(1\dfrac{2}{5}x+\dfrac{3}{7}=\dfrac{-4}{5}\)
d) \(\left|x+\dfrac{2}{3}\right|+2=2\dfrac{1}{3}\)
Tìm x, y sao cho:
a)|x|+|y|= 20
b) |x|+|y|< 20
Tìm giá trị lớn nhất của biểu thức:
a) C = 20013 - \(\left|5-2x\right|\)
b) D = 7 - \(\left|\dfrac{2}{3}+\dfrac{1}{4}x\right|\)
c) N = 1 + \(\dfrac{1}{\left|2x-1\right|}\)
d) E = 13 - ( 2x - \(\dfrac{1}{3}\) )2
e) F = -( 3x + \(\dfrac{1}{2}\) )4 + 2015
g) G = \(\dfrac{2x^2+15}{x^2+3}\)
Tìm x biết
a,\(|\)x+1\(|\)+\(|\)-13\(|\)=26
b,3x+2+3x=250
c,3x-1+5,3x-1=162
d,5x+5x+2=650
bạn nào xong trước mình tick cho nha
a) I x - 2I = x b) I x + 2I = x
c) I x - 3,4 I + I 2,6 - x I =0
d) I x I +x = \(\frac{1}{3}\) e) I x I - x =\(\frac{3}{4}\)
tìm x biết |x-1|+|x+2|=0
BT1: Tìm x, biết:
4) \(\text{|}\text{|}0,4.x-25\%\text{|}-4\text{|}=3\)
5) \(\text{|}x+\dfrac{1}{3}\text{|}+\text{|}x+\dfrac{1}{5}\text{|}+\text{|}x+\dfrac{1}{15}\text{|}=4x\)
1) \(\dfrac{1}{3}-\left(1\dfrac{1}{2}-x\right)=0,3\)
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