-2011+|x|=5.16-81

-2011+|x|=80-81

-2011+|x|=-1

|x|          =(-1)-(-2011)

|x|          =2010

-> x=2010 hoặc x=-2010

-1959.16

( 2,7x - 3/2x ) : 2/7 = -21/4

( 27/10x - 3/2x ) : 2/7 = -21/4

[ x . ( 27/10 - 3/2 ) ] : 2/7 = -21/4

[ x . ( 27/10 - 15/10 ] : 2/7 = -21/4

[ x . 6/5 ] : 2/7 = -21/4

x . 6/5  = -21/4 . 2/7 

x . 6/5 = 3/2

x = 3/2 : 6/5

x =  3/2 . 5/6

x = 15/12

                                                       ĐÚNG KO M.N ?

1. \(450\%+3=\dfrac{9}{2}+3=\dfrac{15}{2}\)

2. \(\dfrac{1}{4}-2,75+2=0,25-2,75+2=-0,5\)

3. \(\dfrac{3}{10}+2,7=0,3+2,7=3\)

a, 12- (-4)= 16
b, 12- (-14)= 26
c, (-13)-(-5)=-8
d, (-2)-(-10)= 8

Tìm giá trị nhỏ nhất hả bạn

Mình thêm đề là tìm Min nhé ^^

Ta có : \(B=\left|2x+16\right|+10\ge10\)

Dấu ''='' xảy ra <=> x = -8 

Vậy GTNN B là 10 <=> x = -8

a. \(8x\left(x-2007\right)-2x+4034=0\)

\(\Rightarrow\left(x-2017\right)\left(4x-1\right)\)

\(\Rightarrow\left[{}\begin{matrix}x-2017=0\\4x-1=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2017\\4x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2017\\x=\dfrac{1}{4}\end{matrix}\right.\)

Vậy x=2017 hoặc x=1/4

b.\(\dfrac{x}{2}+\dfrac{x^2}{8}=0\)

\(\Rightarrow\dfrac{x}{2}\left(1+\dfrac{x}{4}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{x}{2}=0\\1+\dfrac{x}{4}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\\dfrac{x}{4}=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-4\end{matrix}\right.\)

Vậy x=0 hoặc x=-4

c.\(4-x=2\left(x-4\right)^2\)

\(\Rightarrow\left(4-x\right)-2\left(x-4\right)^2=0\)

\(\Rightarrow\left(4-x\right)\left(2x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}4-x=0\\2x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=\dfrac{7}{2}\end{matrix}\right.\)

Vậy x=4 hoặc x=7/2

d.\(\left(x^2+1\right)\left(x-2\right)+2x=4\)

\(\Rightarrow\left(x-2\right)\left(x^2+3\right)=0\)

Nxet: (x²+3)>0 với mọi x

=> x-2=0 <=>x=2

Vậy x=2

a, 8\(x\).(\(x-2007\)) - 2\(x\) + 4034 = 0

     4\(x\)(\(x\) - 2007) - \(x\) + 2017 = 0

     4\(x^2\) - 8028\(x\) - \(x\) + 2017 = 0

     4\(x^2\) - 8029\(x\) + 2017 = 0

     4(\(x^2\) - 2. \(\dfrac{8029}{8}\) \(x\) +( \(\dfrac{8029}{8}\))²) - (\(\dfrac{8029}{4}\))²  + 2017 = 0

    4.(\(x\) + \(\dfrac{8029}{8}\))² = (\(\dfrac{8029}{4}\))² - 2017

       \(\left[{}\begin{matrix}x=-\dfrac{8029}{8}+\dfrac{1}{2}.\sqrt{\left(\dfrac{8029}{4}\right)^2-2017}\\x=-\dfrac{8029}{8}-\dfrac{1}{2}.\sqrt{\left(\dfrac{8029}{4}\right)^2-2017}\end{matrix}\right.\) 

C

C

(1+x)+(2+x)+(3+x)+(4+x)+(5+x)=10*5

(1+2+3+4+5)+ (x+x+x+x+x)=50

15+5*x=50

5*x=50-15

5*x=35

x=35:5=7

(1+x)+(2+x)+(3+x)+(4+x)+(5+x)=10*5

1+x+2+x+3+x+4+x+5+x=50

(1+2+3+4+5)+(x+x+x+x+x)=50

15+5x=50

5x=50-15

5x=35

x=35:5

x=7

\(\dfrac{3x-4}{4}=\dfrac{4x-8}{5}\)

\(\Leftrightarrow\dfrac{3x-4}{4}-\dfrac{4x-8}{5}=0\)

\(\Leftrightarrow\dfrac{5\left(3x-4\right)}{20}-\dfrac{4\left(4x-8\right)}{20}=0\)

\(\Leftrightarrow\dfrac{15x-20}{20}-\dfrac{16x-32}{20}=0\)

\(\Leftrightarrow\dfrac{15x-20-16x+32}{20}=0\)

\(\Leftrightarrow\dfrac{x-12}{20}=0\)

\(\Leftrightarrow x-12=0\)

\(\Leftrightarrow x=12\)