tim x biet
IxI+Ix+2I=0
Tim cac so nguyen x sao cho:
a)Ix+2I+Iy+5I=0
b)IIyI+Ix+2II+IxI=0
a) \(\left|x+2\right|+\left|y+5\right|=0\)
\(\Rightarrow\begin{cases}\left|x+2\right|=0\\\left|y+5\right|=0\end{cases}\)
\(\Rightarrow\begin{cases}x+2=0\\y+5=0\end{cases}\)
\(\Rightarrow\begin{cases}x=-2\\y=-5\end{cases}\)
b) \(\left|\left|y\right|+\left|x+2\right|\right|+\left|x\right|=0\)
\(\Rightarrow\begin{cases}\left|\left|y\right|+\left|x+2\right|\right|=0\\\left|x\right|=0\end{cases}\)
\(\Rightarrow\begin{cases}\left|y\right|+\left|x+2\right|=0\\x=0\end{cases}\)
Thay x = 0 vào biểu thức \(\left|y\right|+\left|x+2\right|=0\), ta đc:
\(\left|y\right|+\left|0+2\right|=0\Rightarrow\left|y\right|+2=0\Rightarrow\left|y\right|=-2\Rightarrow y=\phi\)
Vậy \(x=0;y=\phi\)
Tim x biết:
a.Ix-1I+Ix-2I+Ix-3I+Ix-4I=3
b.Ix-2016yI+Ix-2012I nho hon hoac bang 0
Tim x biet:Ix+1I+Ix+2I+Ix+3I+.....+Ix+2016I=2015x
tim x,y biet Ix-1I+Ix-2I+Iy-3I+Ix-4I=3
ta có:
\(\left|x-1\right|+\left|x-2\right|+\left|y-3\right|+\left|x-4\right|\)
\(=\left|x-1\right|+\left|x-2\right|+\left|y-3\right|+\left|4-x\right|\)
\(\ge\left|x-1+4-x\right|+\left|x-2\right|+\left|y-3\right|\)
\(=3+\left|x-2\right|+\left|y-3\right|\)
\(\ge3\)
Dấu "=" xả ra khi \(\hept{\begin{cases}\left(x-1\right)\left(4-x\right)\ge0\\\left|x-2\right|=0\\\left|y-3\right|=0\end{cases}}\Leftrightarrow\hept{\begin{cases}1\le x\le4\cdot\\x=2\left(TM\cdot\right)\\y=3\end{cases}}\)
Vậy \(x=2;y=3\)
(x-1) + (x-2) + (x-3) + (x-4) = 3
(x+x+x+x) - (1+2+3+4) = 3
X x 4 - 10 = 3
X x 4 = 3 + 10
X x 4 = 13
x = 13 : 4
x = \(\frac{13}{4}\)
tim x nguyen thoa man :Ix+1I+Ix-2I+Ix+7I=5x-10
Ta có:\(\left|x+1\right|\ge0;\left|x-2\right|\ge0;\left|x+7\right|\ge0\)
\(\Rightarrow\left|x+1\right|+\left|x-2\right|+\left|x+7\right|\ge0\)
\(\Rightarrow5x-10\ge0\)
\(\Rightarrow5x\ge10\)
\(\Rightarrow x\ge2\)
\(\Rightarrow\left|x+1\right|=x+1\)
\(\left|x-2\right|=x-2\)
\(\left|x+7\right|=x+7\)
Ta có:\(\left|x+1\right|+\left|x-2\right|+\left|x+7\right|=5x-10\)
\(\Rightarrow x+1+x-2+x+7=5x-10\)
\(\Rightarrow\)\(3x+6=5x-10\)
\(\Rightarrow6+10=5x-3x\)
\(\Rightarrow2x=16\)
\(\Rightarrow x=8\)
Vậy x=8 thỏa mãn
tim x
a.Ix+5I+Ix-4I=4x-2
b.Ix+1I+Ix+2I+...+Ix+2015I=2016x
Tìm x,y
a) Ix-1I + Ix+2I =0
b) I2x-1I + Iy^2-yI = 0
c) Ix+1I + Ix+2I =3
#)Giải :
a) \(\left|x-1\right|+\left|x+2\right|=0\Leftrightarrow\orbr{\begin{cases}x-1=0\\x+2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=1\\x=-2\end{cases}}}\)
b) \(\left|2x-1\right|+\left|y^2-y\right|=0\Leftrightarrow\orbr{\begin{cases}2x-1=0\\y^2-y=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=1\\y^2=y\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{1}{2}\\y\in\left\{-1;0;1\right\}\end{cases}}}\)
tim x:
a,Ix+2I>7
b,Ix-1I<3
Tìm số nguyên x biết:
a)Ix+2I - x = 2
b)Ix-3I+x-3=0
c)Ix+1I + Ix+2I=1
d)Ix-5I+x-8=6
a) /x+2/ - x = 2
=> /x+2/ = 2+x
=> x = 0
b) /x-3/ + x-3 = 0
=> /x-3/ = 0 + x-3 = x- 3
=> x = 0
c) /x+1/ + /x+2/ = 1
<=> /2x/ + 3 = 1
<=> /2x/ = 1- 3 = - 2
=> không có x vì /2x/ ≥ 0
d) /x- 5/ + x - 8 = 6
/x- 5/ + x = 6+8 = 14
=> chịu, bài này mik ko làm dc
=> mí bài kia ko pix có đúng ko nữa